Researchers have shown significant interest in modulating the peroxidase-like activity of nanozymes.Among these,bimetallic nanozymes have shown superior peroxidase-like activity over monometallic counterparts,offering...Researchers have shown significant interest in modulating the peroxidase-like activity of nanozymes.Among these,bimetallic nanozymes have shown superior peroxidase-like activity over monometallic counterparts,offering enhanced performance and cost-efficiency in nanozyme designs.Herein,bimetallic nanozymes comprising nickel(Ni)and osmium(Os)incorporated into hyaluronate(HA)have been developed,resulting in HA-Nin/Os nanoclusters.Subsequently,comprehensive characterizations have been conducted.Further investigation has revealed that HA-Nin/Os efficiently catalyzed 3,3,5,5-tetramethylbenzidine(TMB)oxidation with hydrogen peroxide(H_(2)O_(2)),confirming its peroxidase-like behavior and role as a nanozyme.Impressively,HA-Ni_(2)/Os(Ni/Os=2:1)displays heightened substrate affinity,accelerated reaction rates,enhanced hydroxyl radical production in acidic conditions,and exhibits activity unit of 1224 U/mg,representing more than two-fold increase compared to non-Ni-supported Os nanozyme.Theoretical calculations indicate that Ni support enhances the peroxidase-like process of Os nanozyme by improving H_(2)O_(2) adsorption and TMB oxidation.Crucially,the support of Ni does not significantly alter the other enzyme-like activities of Os nanozymes,thereby enabling Ni to selectively enhance their peroxidase-like activity.In terms of application,the peroxidase-like ability of HA-Ni_(2)/Os,facilitated by HA's carboxyl groups enabling crosslinking,proves effective in a squamous carcinoma antigen immunoassay.Moreover,HA-Ni_(2)/Os exhibit reliable stability,promising as a peroxidase substitute.This work underscores the advantages of incorporating Ni into Os,specifically enhancing peroxidase-like activity,highlighting the potential of Os bimetallic nanozymes for peroxidase-based applications.展开更多
Lateral flow immunoassay(LFIA),a rapid detection technique noted for simplicity and economy,has showcased indispensable applicability in diverse domains such as disease screening,food safety,and environmental monitori...Lateral flow immunoassay(LFIA),a rapid detection technique noted for simplicity and economy,has showcased indispensable applicability in diverse domains such as disease screening,food safety,and environmental monitoring.Nevertheless,challenges still exist in detecting ultra-low concentration analytes due to the inherent sensitivity limitations of LFIA.Recently,significant advances have been achieved by integrating enzyme activity probes and transforming LFIA into a highly sensitive tool for rapidly detecting trace analyte concentrations.Specifically,modifying natural enzymes or engineered nanozymes allows them to function as immune probes,directly catalyzing the production of signal molecules or indirectly initiating enzyme activity.Therefore,the signal intensity and detection sensitivity of LFIA are markedly elevated.The present review undertakes a comprehensive examination of pertinent research literature,offering a systematic analysis of recently proposed enzyme-based signal amplification strategies.By way of comparative assessment,the merits and demerits of current approaches are delineated,along with the identification of research avenues that still need to be explored.It is anticipated that this critical overview will garner considerable attention within the biomedical and materials science communities,providing valuable direction and insight toward the advancement of high-performance LFIA technologies.展开更多
The advancement of various types of fluorescent nanoparticles is crucial for enhancing the application of lateral flow immunoassays(LFIA)across multiple fields.Currently,the fluorescent nanoparticles utilized in LFIA ...The advancement of various types of fluorescent nanoparticles is crucial for enhancing the application of lateral flow immunoassays(LFIA)across multiple fields.Currently,the fluorescent nanoparticles utilized in LFIA predominantly consist of traditional dye-doped nanoparticles or aggregation-induced luminescence dye-doped nanoparticles.The reliance on specific types of nanoparticles limits the diversity of signal reporting groups available for LFIA.Herein,we developed a solid-state luminescent dye-doped nanoparticles(SLDNPs)-based LFIA system with exceptional stability for the detection of C-reactive protein(CRP)in serum.The synthesis of SLD_(520)NP_(S)was simplicity,efficient and eco-friendly,which was ideal for large-scale production of the LFIA test strip.And the SLD_(520)NP_(S)exhibits superior fluorescence quantum yield(49%),fully guarantees the performance of the LFIA test strip.The constructed SLD_(520)NPsm Ab1-based LFIA demonstrated a satisfactory linear relationship with CRP concentrations ranging from 0.5 ng/mL to 100 ng/mL,with limits of detection(LOD)of 0.78 ng/mL and a visible LOD of 1 ng/mL using a handheld 405 nm lamp.Furthermore,the developed LFIA exhibited excellent recoveries in serum,ranging from 94.45%to 102.5%.Overall,the outstanding performance of the SLD_(520)NPs-mAb1-based LFIA indicates that solid-state luminescent dyes have significant potential applications in the field of LFIA.展开更多
Development of accurate analytical protocols for cancer biomarkers is used for the initial prescreening of malignant tumors,disease surveillance,and efficacy assessment with significant clinical benefits.In this work,...Development of accurate analytical protocols for cancer biomarkers is used for the initial prescreening of malignant tumors,disease surveillance,and efficacy assessment with significant clinical benefits.In this work,we reported a liposome-mediated signal-off photoelectrochemical(PEC)immunoassay for the sensitive detection of carcinoembryonic antigen(CEA)using ternary transition metal sulfide CuS/ZnCdS as the photoactive material.Good photocurrents were acquired on the basis of specific oxidation reaction of dopamine on the CuS/ZnCdS.The energy band relationship of CuS/ZnCdS was determined,and the wellmatched oxidation potential of dopamine was verified.To achieve accurate recovery of low-abundance CEA,systematic PEC evaluation from human serum samples was performed by combining with classical immunoreaction and liposome-induced dopamine amplification strategy with high stability and selectivity.Under optimum conditions,PEC immunoassay displayed good photocurrent responses toward target CEA with a dynamic linear range of 0.1-50 ng/mL with a detection limit of 31.6 pg/mL.Importantly,this system by combining with a discussion of energy level matching between semiconductor energy bands and small-molecules opens a new horizon for development of high-efficient PEC immunoassays.展开更多
This study aimed to establish a highly accurate method for quantifying methotrexate(MTX)concentrations in serum using an ultra-high performance liquid chromatography-tandem mass spectrometry system(UPLC-MS/MS)and to c...This study aimed to establish a highly accurate method for quantifying methotrexate(MTX)concentrations in serum using an ultra-high performance liquid chromatography-tandem mass spectrometry system(UPLC-MS/MS)and to compare its performance with the chemiluminescence microparticle immunoassay(CMIA).A total of 211 serum samples from pediatric patients with intracranial tumors undergoing high-dose MTX treatment were analyzed using both techniques.Correlation and agreement analyses were performed to assess the level of concordance between these methods.The results demonstrated a significant correlation(P<0.05)between the two methods,with correlation coefficients of 0.9913 and 0.9893,respectively.However,a statistical difference was noted in MTX serum concentrations at lower levels(0.04-1.5μmol/L),while no significant difference was observed at higher concentrations(1.5-400μmol/L).Specifically,in the 0.04-1.5μmol/L range(107 cases),Bland-Altman analysis indicated a bias of 0.018 between the two methods.Given the observed discrepancies,particularly at lower concentrations,it is advised that the UPLC-MS/MS method should not be used interchangeably with the CMIA assay for therapeutic drug monitoring in patients receiving high-dose MTX treatment.展开更多
The application of pesticides (mostly insecticides and fungicides) during the tea-planting process will undoubtedly increase the dietary risk associated with drinking tea. Thus, it is necessary to ascertain whether pe...The application of pesticides (mostly insecticides and fungicides) during the tea-planting process will undoubtedly increase the dietary risk associated with drinking tea. Thus, it is necessary to ascertain whether pesticide residues in tea products exceed the maximum residue limits. However, the complex matrices present in tea samples comprise a major challenge in the analytical detection of pesticide residues. In this study, nine types of lateral flow immunochromatographic strips (LFICSs) were developed to detect the pesticides of interest (fenpropathrin, chlorpyrifos, imidacloprid, thiamethoxam, acetamiprid, carbendazim, chlorothalonil, pyraclostrobin, and iprodione). To reduce the interference of tea substrates on the assay sensitivity, the pretreatment conditions for tea samples, including the extraction solvent, extraction time, and purification agent, were optimized for the simultaneous detection of these pesticides. The entire testing procedure (including pretreatment and detection) could be completed within 30 min. The detected results of authentic tea samples were confirmed by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), which suggest that the LFICS coupled with sample rapid pretreatment can be used for on-site rapid screening of the target pesticide in tea products prior to their market release.展开更多
Foods are often contaminated by multiple foodborne pathogens,which threatens human health.In this work,we developed a microfluidic biosensor for multiplex immunoassay of foodborne bacteria with agitation driven by pro...Foods are often contaminated by multiple foodborne pathogens,which threatens human health.In this work,we developed a microfluidic biosensor for multiplex immunoassay of foodborne bacteria with agitation driven by programmed audio signals.This agitation,powered by the vibration of a speaker cone during music playing,accelerated the mass transport in the incubation process to form bacterial complexes within 10 min.Immunoassay reagents of the two target bacteria(Escherichia coli O157:H7 and Salmonella typhimurium)were preloaded into the corresponding fore-vacuum storage chamber on the chip,and released to participate in the subsequent immune analysis process by piercing the chambers.All the detection processes were integrated into a single microfluidic chip and controlled by a smartphone through Bluetooth.Under selected conditions,wide linear ranges and low limits of detection(LODs<2CFU/m L)were obtained,and real food samples were successfully determined within 30 min.This biosensing method can be extended to wide-ranging applications by loading different recognizing reagents.展开更多
[Objectives]This study was conducted to explore rapid and large-scale screening and detection of peste des petits ruminants(PPR),so as to provide important technical means for prevention,control and purification of PP...[Objectives]This study was conducted to explore rapid and large-scale screening and detection of peste des petits ruminants(PPR),so as to provide important technical means for prevention,control and purification of PPR.[Methods]Soluble N protein and NH fusion protein were successfully obtained in an Escherichia coli expression system by optimizing E.coli codon and expression conditions.Furthermore,based on purified soluble N protein and NH fusion protein,a double-antigen sandwich time-resolved fluorescence immunoassay method for detection of peste des petits ruminants virus(PPRV)was established.[Results]The method has high sensitivity and specificity and can specifically detect the antibody against PPRV in sheep serum,and it has no cross reaction with other related diseases.The method was used to detect 292 clinical samples,and compared with French IDVET competition ELISA kit.The coincidence rates of positive samples and negative samples from the two kinds of test kits were 92.47%and 97.26%,respectively,and the overall coincidence rate was 94.86%.The intra-group and inter-group coefficients of variation in the repeatability test were less than 10%.[Conclusions]Compared with the traditional ELISA method,the double-antigen sandwich time-resolved fluorescence immunoassay for detection of PPRV has equivalent sensitivity and specificity,and simple and rapid operation,and thus high application and popularization value.展开更多
Immunoassay technology is an analytical method with high sensitivity and specificity; it provides a technique to assay materials which cannot be measured by other methods, or are difficult to detect. It plays a very i...Immunoassay technology is an analytical method with high sensitivity and specificity; it provides a technique to assay materials which cannot be measured by other methods, or are difficult to detect. It plays a very important role in biological sample pre-treatment, therapeutic drug monitoring and drug determination, and is one of the important means for in vivo drug analyses. This paper reviews immunoassays commonly used in bioanalysis, including immunoextraction and immunodepletion for pretreatment of biological samples, conventional immunoassay methods and new immunoassay technologies for determination of target drugs.展开更多
Objective: This study aimed to establish chemiluminescent immunoassay (CLIA) for quantitative determination of theophylline levels in human serum. Methods: To measure the concentration of theophylline (n=122) and eval...Objective: This study aimed to establish chemiluminescent immunoassay (CLIA) for quantitative determination of theophylline levels in human serum. Methods: To measure the concentration of theophylline (n=122) and evaluate the assay.Results: The linear range of the CLIA method was 0.51～40 mg/L (Y=1.02X+0.44, r=0.995). The intra and inter CV (coefficient variance) of CLIA were 3.20% and 3.57%, respectively. The average recovery rate was 102.3%. This method was free from interference by brilirubin (＜200 μmol/L), hemoglobin (＜10 g/L), and triglycerides (＜15 mmol/L). Conclusion: This method is simple, convenient and precise for clinical pharmacokinetics study oftheophylline.展开更多
Objective: to analyze the immunoassay of thyroid cancer patients by chemiluminescence immunology method. Methods: from March 2020 to March 20, the investigation of the thyroid cancer patients were selected as the rese...Objective: to analyze the immunoassay of thyroid cancer patients by chemiluminescence immunology method. Methods: from March 2020 to March 20, the investigation of the thyroid cancer patients were selected as the research object, and based on the methods of digital random each group of 75 patients were divided into two groups in patients undergoing immune to enjoy chemiluminescence immune method, and the control group patients by analyzing radiation immunology, during this time they register for two separate immunological analysis time. The levels of thyroglobulin were examined, and the diagnostic accuracy was calculated and compared. Results: the detection levels of S. thiococcus in the observation group and the control group were 701.87±80.23 μ g/L and 637.68±65.17% μ g/L, respectively. Immunological examination was 27.63±4.12 minutes and 36.22±5.37 minutes, respectively. The diagnostic accuracy coefficients were 96.00 and 88.00%, respectively. Conclusion: the chemiluminescence immunoassay can not only reduce the test time, but also increase the accuracy of the test to some extent, so it needs to be used in clinic.展开更多
A fluorescence polarization immunoassay （FPIA） was developed for the analysis ofaflatoxins （AFs） using an anti-aflatoxin B1 （AFB1） monoclonal antibody and a novel fluorescein-labeled AFB1 tracer. The FPIA showed...A fluorescence polarization immunoassay （FPIA） was developed for the analysis ofaflatoxins （AFs） using an anti-aflatoxin B1 （AFB1） monoclonal antibody and a novel fluorescein-labeled AFB1 tracer. The FPIA showed an IC50 value of 23.33 ng/mL with a limit of detection of 13.12 ng/mL for AFB1. The cross-reactivities of AFB1, AFB2, AFG1, AFG2, AFM1, and AFM2 with the antibody were 100%, 65.7%, 143%, 23.5%, 111.4%, and 2%, respectively. The group-specificity of anti-AFB1mAb indicated that the FPIA could potentially be used in a screening method for the detection of total AFs, albeit not AFG2 and AFM2. The total time required for analyzing 96 samples in one microplate was less than 5 rain. This study demonstrates the potential usefulness of the FPIA as a rapid and simple technique for monitoring AFs.展开更多
AIM: To establish a convenient immunoassay method based on recombinant antigen preS1(21-119aa) to detect anti-preS1 antibodies and evaluate the clinical significance of antibodies in hepatitis B. METHODS: The expressi...AIM: To establish a convenient immunoassay method based on recombinant antigen preS1(21-119aa) to detect anti-preS1 antibodies and evaluate the clinical significance of antibodies in hepatitis B. METHODS: The expression plasmid pET-28a-preS1 was constructed, and a large quantity of preS1(21-119aa) fragment of the large HBsAg protein was obtained. The preS1 fragment purified by Ni(2+)-IDA affinity chromatography was used as coated antigen to establish the indirect ELISA based on streptavidin-biotin system for detection of the anti-preS1 antibodies in sera from HBV-infected patients. For follow-up study, serial sera were collected during the clinical course of 21 HBV-infected patients and anti-preS1 antibodies, preS1 antigen, HBV-DNA and other serological HBV markers were analyzed. RESULTS: preS1(21-119aa) fragment was highly expressed from the plasmid pET-28a-preS1 in a soluble form in E.Coli (30mg.L(-1)), and easily purified to high purity over 90% by one step of Ni(2+)-IDA-sepharose 6B affinity chromatography. The purity and antigenicity of the purified preS1(21-119aa) protein was determined by 150g.L(-1) SDS-PAGE, Western blot and a direct ELISA. Recombinant preS1(21-119aa) protein was successfully applied in the immunoassay which could sensitively detect the anti-preS1 antibodies in serum specimens of acute or chronic hepatitis B patients. Results showed that more than half of 19 acute hepatitis B patients produced anti-preS1 antibodies during recovery of the disease, however, the response was only found in a few of chronic patients. In the clinical follow-up study of 11 patients with anti-preS1 positive serological profile, HBsAg and HBV-DNA clearance occurred in 6 of 10 acute hepatitis B patients in 5-6 months, and seroconversion of HBeAg and disappearance of HBV-DNA occurred in 1 chronic patients treated with lavumidine, a antiviral agent. CONCLUSION: The high-purity preS1(21-119aa) coated antigen was successfully prepared by gene expression and affinity chromatography. Using this antigen, a conveniently detective system of anti-preS1 antibodies in sera was established. Preliminarily clinical trial the occurrence of anti-preS1 antibodies in acute hepatitis B patients suggests the clearance of HBV from serum in a short-term time, and anti-preS1 positive in chronic patients means health improvement or recovery from the disease.展开更多
Aflatoxin B_(1)(AFB_(1))is one of the most toxic,mutagenic and carcinogenic mycotoxin,widely exists in contaminated food,grains and feedstuff products.In this study,a novel magnetic beads multicolor colorimetric immun...Aflatoxin B_(1)(AFB_(1))is one of the most toxic,mutagenic and carcinogenic mycotoxin,widely exists in contaminated food,grains and feedstuff products.In this study,a novel magnetic beads multicolor colorimetric immunoassay(MBMCIA)based on Au@Ag nanorods(Au@Ag NRs)is proposed to visual detect ultralow concentration of AFB_(1)with high-resolution by the naked-eye.To design the MBMCIA system,AFB_(1)-BSA conjugates were first coated on the surface of magnetic beads(MBs),then alkaline phosphatase(ALP)as a bridge between immunoassay a nd color reaction was used for catalytic hydrolysis of ascorbic acid-phosphate to generate reductive ascorbic acid.Finally,the yielded ascorbic acid could reduce silver ions to grow a silver coating on the surface of gold nanorods to generate Au@Ag NRs,which leads to the bule-shifted longitudinal absorption peak of Au NRs,accompanying with a series of perceptible color change.Under the optimal conditions,the proposed MBMCIA exhibited go od sensitivity and specificity for the detection of AFB_(1)with the detection limit as low as 5.7 pg/mL Meanwhile,the MBMCIA was also applied for the analysis of AFB_(1)in spiked wheat samples,the obtained recoveries range from 99.1%to 104.3%with relative standard deviation(RSD)less than 7.05%were acceptable.The proposed MBMCIA integrates separated,enriched,anti-interfe rence and signal read-out into one,which opens up a new avenue for an on-site visual food safety inspection or environmental monitoring.展开更多
Glypican-3 （GPC3） is reported as a great promising tumor marker for hepatocellular carcinoma （HCC） diagnosis. Highly sensitive and accurate analysis of serum GPC3 （sGPC3）, in combination with or instead of tradi...Glypican-3 （GPC3） is reported as a great promising tumor marker for hepatocellular carcinoma （HCC） diagnosis. Highly sensitive and accurate analysis of serum GPC3 （sGPC3）, in combination with or instead of traditional HCC marker alpha-fetoprotein （AFP）, is essential for early diagnosis of I-ICC. Biomaterial-functionalized magnetic particles have been utilized as solid supports with good biological compatibility for sensitive immunoassay. Here, the magnetic nanoparticles （MnPs） and magnetic microparticles （MmPs） with carboxyl groups were further modified with streptavidin, and applied for the development of chemiluminescence enzyme immunoassay （CLEIA）. After comparing between MnPs- and MmPs-based CLEIA, MnPs-based CLEIA was proved to be a better method with less assay time, greater sensitivity, better linearity and longer chemiluminescence platform. MnPs-based CLEIA was applied for detection of sGPC3 in normal liver, hepatocirrhosis, secondary liver cancer and HCC serum samples. The results indicated that sGPC3 was effective in diagnosis of HCC with high performance.展开更多
Lateral flow immunoassay(LFIA) is a widely used express method and offers advantages such as a short analysis time, simplicity of testing and result evaluation.However, an LFIA based on gold nanospheres lacks the desi...Lateral flow immunoassay(LFIA) is a widely used express method and offers advantages such as a short analysis time, simplicity of testing and result evaluation.However, an LFIA based on gold nanospheres lacks the desired sensitivity, thereby limiting its wide applications.In this study, spherical nanogold labels along with new types of nanogold labels such as gold nanopopcorns and nanostars were prepared, characterized, and applied for LFIA of model protein antigen procalcitonin. It was found that the label with a structure close to spherical provided more uniform distribution of specific antibodies on its surface, indicative of its suitability for this type of analysis.LFIA using gold nanopopcorns as a label allowed procalcitonin detection over a linear range of 0.5–10 ng mL^(-1) with the limit of detection of 0.1 ng mL^(-1), which was fivefold higher than the sensitivity of the assay with gold nanospheres. Another approach to improve the sensitivity of the assay included the silver enhancement method,which was used to compare the amplification of LFIA for procalcitonin detection. The sensitivity of procalcitonin determination by this method was 10 times better the sensitivity of the conventional LFIA with gold nanosphere as a label. The proposed approach of LFIA based on gold nanopopcorns improved the detection sensitivity without additional steps and prevented the increased consumption of specific reagents(antibodies).展开更多
A chemiluminescence enzyme immunoassay based on magnetic microparticles (MmPs-CLEIA) was developed to evaluate serum a-fetoprotein (AFP) in parallel with traditional colorimetric enzyme-linked immunosorbent assay (ELI...A chemiluminescence enzyme immunoassay based on magnetic microparticles (MmPs-CLEIA) was developed to evaluate serum a-fetoprotein (AFP) in parallel with traditional colorimetric enzyme-linked immunosorbent assay (ELISA).A systematic comparison between the MmPs-CLEIA and colorimetric ELISA concluded that the MPs-CLEIA exhibited fewer dosages of immunoreagents,less total assay time,and better linearity,recovery,precision,sensitivity and validity.AFP was detected in forty human serum samples by the proposed MPs-CLEIA and ELISA,and the results were compared with commercial electrochemiluminescence immunoassay (ECLIA) kit.The correlation coefficient between MPs-CLEIA and ELISA was obtained with R 2 0.6703;however,the correlation between MPs-CLEIA and ECLIA (R 2 0.9582) was obviously better than that between colorimetric ELISA and ECLIA (R 2 0.6866).展开更多
DNA methyltransferase 1(DNMT1)is a useful biomarker for lung cancer in early clinical diagnosis.A rapid magnetic chemiluminescence immunoassay(MCLIA)for DNMT1 in human serum has been developed.Horseradish peroxidase(H...DNA methyltransferase 1(DNMT1)is a useful biomarker for lung cancer in early clinical diagnosis.A rapid magnetic chemiluminescence immunoassay(MCLIA)for DNMT1 in human serum has been developed.Horseradish peroxidase(HRP)-second-Ab was used to labeled polyclonal antibodies of anti-DNMT1.DNMT1 in sample integrates with specific immunomagnetic beads and can constitute a supersandwiched immunoreaction.In magnetic field,nonspecific materials can be separated.After luminescent substrate luminol-H2O2-BIP was added,the relative light unit(RLU)of HRP was detected and was discovered to be directly proportional to the content of DNMT1 in sample.The correlative variables involved in the MCLIA value were optimized and the methodological evaluation was carried out.After optimization,in the range of0.5–128 ng/mL,the linear regression equation was y=0.5014 x+1.769(x was logCDNMT1,y was relative luminescence units(RLU)/RLU0),and the limit of detection was 0.01 ng/mL.The RSD of intra-and interassays were 15.8%–16.9%and 14.3%–18.1%,respectively.The recovery was from 70.0%to 106.2%.Furthermore,paralleled with purchasable enzyme-linked immunosorbent assay(ELISA)kits,MCLEIA had lower detection limit,wider linear range and shorter detection time.Therefore,the MCLEIA established in this study could be used for the sensitive detection of DNMT1 in serum sample.展开更多
The detection of chemical contaminants is critical to ensure dairy safety. These contaminants include veterinary medicines, antibiotics, pesticides, heavy metals, mycotoxins, and persistent organic pollutants （POPs）...The detection of chemical contaminants is critical to ensure dairy safety. These contaminants include veterinary medicines, antibiotics, pesticides, heavy metals, mycotoxins, and persistent organic pollutants （POPs）. Immunoassays have recently been used to detect contaminants in milk because of their simple operation, high speed, and low cost. This article describes the latest developments in the most important component of immunoassays--antibodies, and then reviews the four major substrates used for immunoassays （i.e., microplates, membranes, gels, and chips） as well as their use in the detection of milk contaminants. The paper concludes with prospects for further aDDlications of these immunoassavs.展开更多
A strip reader based lateral flow immunoassay （LFIA） was established for the rapid and quantitative detection of ractopamine （RAC） in swine urine. The ratio of the optical densities （ODs） of the test line （AT）...A strip reader based lateral flow immunoassay （LFIA） was established for the rapid and quantitative detection of ractopamine （RAC） in swine urine. The ratio of the optical densities （ODs） of the test line （AT） to that of the control line （Ac） was used to effectively minimize interference among strips and sample variations. The linear range for the quantitative detection of RAC was 0.2 ng/mL to 3.5 ng/mL with a median inhibitory concentration （IC50） of 0.59＋0.06 ng/mL. The limit of detection （LOD） of the LFIA was 0.13 ng/mL. The intra-assay recovery rates were 92.97%, 97.25%, and 107.41%, whereas the inter-assay rates were 80.07%, 108.17%, and 93.7%, respectively.展开更多
基金financial support from the Natural Science Foundation of Fujian Province(No.2022J01271)the Joint Funds for the Innovation of Science and Technology,Fujian Province(No.2023Y9226)+1 种基金the Introduced High-Level Talent Team Project of Quanzhou City(No.2023CT008)the Doctoral Research Foundation Project of the Second Affiliated Hospital of Fujian Medical University(No.BS202201)。
文摘Researchers have shown significant interest in modulating the peroxidase-like activity of nanozymes.Among these,bimetallic nanozymes have shown superior peroxidase-like activity over monometallic counterparts,offering enhanced performance and cost-efficiency in nanozyme designs.Herein,bimetallic nanozymes comprising nickel(Ni)and osmium(Os)incorporated into hyaluronate(HA)have been developed,resulting in HA-Nin/Os nanoclusters.Subsequently,comprehensive characterizations have been conducted.Further investigation has revealed that HA-Nin/Os efficiently catalyzed 3,3,5,5-tetramethylbenzidine(TMB)oxidation with hydrogen peroxide(H_(2)O_(2)),confirming its peroxidase-like behavior and role as a nanozyme.Impressively,HA-Ni_(2)/Os(Ni/Os=2:1)displays heightened substrate affinity,accelerated reaction rates,enhanced hydroxyl radical production in acidic conditions,and exhibits activity unit of 1224 U/mg,representing more than two-fold increase compared to non-Ni-supported Os nanozyme.Theoretical calculations indicate that Ni support enhances the peroxidase-like process of Os nanozyme by improving H_(2)O_(2) adsorption and TMB oxidation.Crucially,the support of Ni does not significantly alter the other enzyme-like activities of Os nanozymes,thereby enabling Ni to selectively enhance their peroxidase-like activity.In terms of application,the peroxidase-like ability of HA-Ni_(2)/Os,facilitated by HA's carboxyl groups enabling crosslinking,proves effective in a squamous carcinoma antigen immunoassay.Moreover,HA-Ni_(2)/Os exhibit reliable stability,promising as a peroxidase substitute.This work underscores the advantages of incorporating Ni into Os,specifically enhancing peroxidase-like activity,highlighting the potential of Os bimetallic nanozymes for peroxidase-based applications.
基金Financial supports from the National Natural Science Foundation of China(NSFC,Nos.52272144 and 22205048)Heilongjiang Provincial Natural Science Foundation of China(No.JQ2022E001)+3 种基金China Postdoctoral Science Foundation(Nos.2022M710931 and 2023T160154)Heilongjiang Postdoctoral Science Foundation(No.LBH-Z22010)Natural Science Foundation of Shandong Province(No.ZR2020ZD42)the Fundamental Research funds for the Central Universities are greatly acknowledged.
文摘Lateral flow immunoassay(LFIA),a rapid detection technique noted for simplicity and economy,has showcased indispensable applicability in diverse domains such as disease screening,food safety,and environmental monitoring.Nevertheless,challenges still exist in detecting ultra-low concentration analytes due to the inherent sensitivity limitations of LFIA.Recently,significant advances have been achieved by integrating enzyme activity probes and transforming LFIA into a highly sensitive tool for rapidly detecting trace analyte concentrations.Specifically,modifying natural enzymes or engineered nanozymes allows them to function as immune probes,directly catalyzing the production of signal molecules or indirectly initiating enzyme activity.Therefore,the signal intensity and detection sensitivity of LFIA are markedly elevated.The present review undertakes a comprehensive examination of pertinent research literature,offering a systematic analysis of recently proposed enzyme-based signal amplification strategies.By way of comparative assessment,the merits and demerits of current approaches are delineated,along with the identification of research avenues that still need to be explored.It is anticipated that this critical overview will garner considerable attention within the biomedical and materials science communities,providing valuable direction and insight toward the advancement of high-performance LFIA technologies.
基金supported by the National Natural Science Foundation of China(Nos.22064014,21765013)the Science and Technology Development Plan Project of Lanzhou(No.20211-146)+3 种基金the Science and Technology Project of Gansu Province(Nos.21YF5FA071,21JR7RA538)the Industrial Support Programme for Higher Education Institutions Project(Nos.2023CYZC-69,2024CYCZ-05)the 2023 Gansu Provincial Key Talent Project(No.2023RCXM26)a Gansu province postdoctoral grant(No.00247)。
文摘The advancement of various types of fluorescent nanoparticles is crucial for enhancing the application of lateral flow immunoassays(LFIA)across multiple fields.Currently,the fluorescent nanoparticles utilized in LFIA predominantly consist of traditional dye-doped nanoparticles or aggregation-induced luminescence dye-doped nanoparticles.The reliance on specific types of nanoparticles limits the diversity of signal reporting groups available for LFIA.Herein,we developed a solid-state luminescent dye-doped nanoparticles(SLDNPs)-based LFIA system with exceptional stability for the detection of C-reactive protein(CRP)in serum.The synthesis of SLD_(520)NP_(S)was simplicity,efficient and eco-friendly,which was ideal for large-scale production of the LFIA test strip.And the SLD_(520)NP_(S)exhibits superior fluorescence quantum yield(49%),fully guarantees the performance of the LFIA test strip.The constructed SLD_(520)NPsm Ab1-based LFIA demonstrated a satisfactory linear relationship with CRP concentrations ranging from 0.5 ng/mL to 100 ng/mL,with limits of detection(LOD)of 0.78 ng/mL and a visible LOD of 1 ng/mL using a handheld 405 nm lamp.Furthermore,the developed LFIA exhibited excellent recoveries in serum,ranging from 94.45%to 102.5%.Overall,the outstanding performance of the SLD_(520)NPs-mAb1-based LFIA indicates that solid-state luminescent dyes have significant potential applications in the field of LFIA.
基金financial support from the National Natural Science Foundation of China(Nos.22274022 and 21874022).
文摘Development of accurate analytical protocols for cancer biomarkers is used for the initial prescreening of malignant tumors,disease surveillance,and efficacy assessment with significant clinical benefits.In this work,we reported a liposome-mediated signal-off photoelectrochemical(PEC)immunoassay for the sensitive detection of carcinoembryonic antigen(CEA)using ternary transition metal sulfide CuS/ZnCdS as the photoactive material.Good photocurrents were acquired on the basis of specific oxidation reaction of dopamine on the CuS/ZnCdS.The energy band relationship of CuS/ZnCdS was determined,and the wellmatched oxidation potential of dopamine was verified.To achieve accurate recovery of low-abundance CEA,systematic PEC evaluation from human serum samples was performed by combining with classical immunoreaction and liposome-induced dopamine amplification strategy with high stability and selectivity.Under optimum conditions,PEC immunoassay displayed good photocurrent responses toward target CEA with a dynamic linear range of 0.1-50 ng/mL with a detection limit of 31.6 pg/mL.Importantly,this system by combining with a discussion of energy level matching between semiconductor energy bands and small-molecules opens a new horizon for development of high-efficient PEC immunoassays.
基金The Science and Technology Fund of Beijing Shijitan Hospital(Grant No.2022-C06)the National Key Research and Development Program of China(Grant No.2020YFF01014606).
文摘This study aimed to establish a highly accurate method for quantifying methotrexate(MTX)concentrations in serum using an ultra-high performance liquid chromatography-tandem mass spectrometry system(UPLC-MS/MS)and to compare its performance with the chemiluminescence microparticle immunoassay(CMIA).A total of 211 serum samples from pediatric patients with intracranial tumors undergoing high-dose MTX treatment were analyzed using both techniques.Correlation and agreement analyses were performed to assess the level of concordance between these methods.The results demonstrated a significant correlation(P<0.05)between the two methods,with correlation coefficients of 0.9913 and 0.9893,respectively.However,a statistical difference was noted in MTX serum concentrations at lower levels(0.04-1.5μmol/L),while no significant difference was observed at higher concentrations(1.5-400μmol/L).Specifically,in the 0.04-1.5μmol/L range(107 cases),Bland-Altman analysis indicated a bias of 0.018 between the two methods.Given the observed discrepancies,particularly at lower concentrations,it is advised that the UPLC-MS/MS method should not be used interchangeably with the CMIA assay for therapeutic drug monitoring in patients receiving high-dose MTX treatment.
基金supported by grants from Shanghai Agriculture Applied Technology Development Program,China(Grant No.:2020-02-08-00-08-F01456)the Key Research and Development Program of Zhejiang Province,China(Grant No.:2020C02024-2).
文摘The application of pesticides (mostly insecticides and fungicides) during the tea-planting process will undoubtedly increase the dietary risk associated with drinking tea. Thus, it is necessary to ascertain whether pesticide residues in tea products exceed the maximum residue limits. However, the complex matrices present in tea samples comprise a major challenge in the analytical detection of pesticide residues. In this study, nine types of lateral flow immunochromatographic strips (LFICSs) were developed to detect the pesticides of interest (fenpropathrin, chlorpyrifos, imidacloprid, thiamethoxam, acetamiprid, carbendazim, chlorothalonil, pyraclostrobin, and iprodione). To reduce the interference of tea substrates on the assay sensitivity, the pretreatment conditions for tea samples, including the extraction solvent, extraction time, and purification agent, were optimized for the simultaneous detection of these pesticides. The entire testing procedure (including pretreatment and detection) could be completed within 30 min. The detected results of authentic tea samples were confirmed by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), which suggest that the LFICS coupled with sample rapid pretreatment can be used for on-site rapid screening of the target pesticide in tea products prior to their market release.
基金supported financially by“Kunlun Talents High-end Innovation and Entrepreneurship Talents”of Qinghai Province in 2022National Natural Science Foundation of China(Nos.22322401 and 82073816)Beijing Nova Program(No.20220484055)。
文摘Foods are often contaminated by multiple foodborne pathogens,which threatens human health.In this work,we developed a microfluidic biosensor for multiplex immunoassay of foodborne bacteria with agitation driven by programmed audio signals.This agitation,powered by the vibration of a speaker cone during music playing,accelerated the mass transport in the incubation process to form bacterial complexes within 10 min.Immunoassay reagents of the two target bacteria(Escherichia coli O157:H7 and Salmonella typhimurium)were preloaded into the corresponding fore-vacuum storage chamber on the chip,and released to participate in the subsequent immune analysis process by piercing the chambers.All the detection processes were integrated into a single microfluidic chip and controlled by a smartphone through Bluetooth.Under selected conditions,wide linear ranges and low limits of detection(LODs<2CFU/m L)were obtained,and real food samples were successfully determined within 30 min.This biosensing method can be extended to wide-ranging applications by loading different recognizing reagents.
基金Supported by National Key R&D Program for the Prevention and Control of Major Exotic Animal Diseases(2022YFD1800500)National Mutton Sheep Industrial Technology System(CARS39)+2 种基金Key Research and Development Program of Shandong Province(Major Science and Technology Innovation Project)(2021CXGC011306)Scientific Research Project of General Administration of Customs(2024HK033)Scientific Research Project of Jinan Customs(2023JK005).
文摘[Objectives]This study was conducted to explore rapid and large-scale screening and detection of peste des petits ruminants(PPR),so as to provide important technical means for prevention,control and purification of PPR.[Methods]Soluble N protein and NH fusion protein were successfully obtained in an Escherichia coli expression system by optimizing E.coli codon and expression conditions.Furthermore,based on purified soluble N protein and NH fusion protein,a double-antigen sandwich time-resolved fluorescence immunoassay method for detection of peste des petits ruminants virus(PPRV)was established.[Results]The method has high sensitivity and specificity and can specifically detect the antibody against PPRV in sheep serum,and it has no cross reaction with other related diseases.The method was used to detect 292 clinical samples,and compared with French IDVET competition ELISA kit.The coincidence rates of positive samples and negative samples from the two kinds of test kits were 92.47%and 97.26%,respectively,and the overall coincidence rate was 94.86%.The intra-group and inter-group coefficients of variation in the repeatability test were less than 10%.[Conclusions]Compared with the traditional ELISA method,the double-antigen sandwich time-resolved fluorescence immunoassay for detection of PPRV has equivalent sensitivity and specificity,and simple and rapid operation,and thus high application and popularization value.
基金National Natural Science Foundation of China(Gr ant No.81102499)Hunan Science and Technology Project(Grant No.2011SK3261)
文摘Immunoassay technology is an analytical method with high sensitivity and specificity; it provides a technique to assay materials which cannot be measured by other methods, or are difficult to detect. It plays a very important role in biological sample pre-treatment, therapeutic drug monitoring and drug determination, and is one of the important means for in vivo drug analyses. This paper reviews immunoassays commonly used in bioanalysis, including immunoextraction and immunodepletion for pretreatment of biological samples, conventional immunoassay methods and new immunoassay technologies for determination of target drugs.
文摘Objective: This study aimed to establish chemiluminescent immunoassay (CLIA) for quantitative determination of theophylline levels in human serum. Methods: To measure the concentration of theophylline (n=122) and evaluate the assay.Results: The linear range of the CLIA method was 0.51～40 mg/L (Y=1.02X+0.44, r=0.995). The intra and inter CV (coefficient variance) of CLIA were 3.20% and 3.57%, respectively. The average recovery rate was 102.3%. This method was free from interference by brilirubin (＜200 μmol/L), hemoglobin (＜10 g/L), and triglycerides (＜15 mmol/L). Conclusion: This method is simple, convenient and precise for clinical pharmacokinetics study oftheophylline.
文摘Objective: to analyze the immunoassay of thyroid cancer patients by chemiluminescence immunology method. Methods: from March 2020 to March 20, the investigation of the thyroid cancer patients were selected as the research object, and based on the methods of digital random each group of 75 patients were divided into two groups in patients undergoing immune to enjoy chemiluminescence immune method, and the control group patients by analyzing radiation immunology, during this time they register for two separate immunological analysis time. The levels of thyroglobulin were examined, and the diagnostic accuracy was calculated and compared. Results: the detection levels of S. thiococcus in the observation group and the control group were 701.87±80.23 μ g/L and 637.68±65.17% μ g/L, respectively. Immunological examination was 27.63±4.12 minutes and 36.22±5.37 minutes, respectively. The diagnostic accuracy coefficients were 96.00 and 88.00%, respectively. Conclusion: the chemiluminescence immunoassay can not only reduce the test time, but also increase the accuracy of the test to some extent, so it needs to be used in clinic.
基金supported by grants from the International Science&Technology Cooperation Program of China(2009DFA32330)the Special Fund for Agro-scientific Research in the Public Interest(No.201203040)
文摘A fluorescence polarization immunoassay （FPIA） was developed for the analysis ofaflatoxins （AFs） using an anti-aflatoxin B1 （AFB1） monoclonal antibody and a novel fluorescein-labeled AFB1 tracer. The FPIA showed an IC50 value of 23.33 ng/mL with a limit of detection of 13.12 ng/mL for AFB1. The cross-reactivities of AFB1, AFB2, AFG1, AFG2, AFM1, and AFM2 with the antibody were 100%, 65.7%, 143%, 23.5%, 111.4%, and 2%, respectively. The group-specificity of anti-AFB1mAb indicated that the FPIA could potentially be used in a screening method for the detection of total AFs, albeit not AFG2 and AFM2. The total time required for analyzing 96 samples in one microplate was less than 5 rain. This study demonstrates the potential usefulness of the FPIA as a rapid and simple technique for monitoring AFs.
基金the grants No.KY951-Al-301 and No.KY95T-06-03 from the 9th Five Years Plan Key Research Programs of the Chinese Academy of Sciences.
文摘AIM: To establish a convenient immunoassay method based on recombinant antigen preS1(21-119aa) to detect anti-preS1 antibodies and evaluate the clinical significance of antibodies in hepatitis B. METHODS: The expression plasmid pET-28a-preS1 was constructed, and a large quantity of preS1(21-119aa) fragment of the large HBsAg protein was obtained. The preS1 fragment purified by Ni(2+)-IDA affinity chromatography was used as coated antigen to establish the indirect ELISA based on streptavidin-biotin system for detection of the anti-preS1 antibodies in sera from HBV-infected patients. For follow-up study, serial sera were collected during the clinical course of 21 HBV-infected patients and anti-preS1 antibodies, preS1 antigen, HBV-DNA and other serological HBV markers were analyzed. RESULTS: preS1(21-119aa) fragment was highly expressed from the plasmid pET-28a-preS1 in a soluble form in E.Coli (30mg.L(-1)), and easily purified to high purity over 90% by one step of Ni(2+)-IDA-sepharose 6B affinity chromatography. The purity and antigenicity of the purified preS1(21-119aa) protein was determined by 150g.L(-1) SDS-PAGE, Western blot and a direct ELISA. Recombinant preS1(21-119aa) protein was successfully applied in the immunoassay which could sensitively detect the anti-preS1 antibodies in serum specimens of acute or chronic hepatitis B patients. Results showed that more than half of 19 acute hepatitis B patients produced anti-preS1 antibodies during recovery of the disease, however, the response was only found in a few of chronic patients. In the clinical follow-up study of 11 patients with anti-preS1 positive serological profile, HBsAg and HBV-DNA clearance occurred in 6 of 10 acute hepatitis B patients in 5-6 months, and seroconversion of HBeAg and disappearance of HBV-DNA occurred in 1 chronic patients treated with lavumidine, a antiviral agent. CONCLUSION: The high-purity preS1(21-119aa) coated antigen was successfully prepared by gene expression and affinity chromatography. Using this antigen, a conveniently detective system of anti-preS1 antibodies in sera was established. Preliminarily clinical trial the occurrence of anti-preS1 antibodies in acute hepatitis B patients suggests the clearance of HBV from serum in a short-term time, and anti-preS1 positive in chronic patients means health improvement or recovery from the disease.
基金supported by the National Natural Science Foundation of China(Nos.21804022,21964003 and 81773894)the Natural Science Foundation of Jiangxi Province(No.20202BABL213019)+1 种基金the Science and Technology Project of the Education Department of Jiangxi Province of China(No.GJJ190775)the Special Graduate Student Innovation Fund of Jiangxi Province(No.CX190013)。
文摘Aflatoxin B_(1)(AFB_(1))is one of the most toxic,mutagenic and carcinogenic mycotoxin,widely exists in contaminated food,grains and feedstuff products.In this study,a novel magnetic beads multicolor colorimetric immunoassay(MBMCIA)based on Au@Ag nanorods(Au@Ag NRs)is proposed to visual detect ultralow concentration of AFB_(1)with high-resolution by the naked-eye.To design the MBMCIA system,AFB_(1)-BSA conjugates were first coated on the surface of magnetic beads(MBs),then alkaline phosphatase(ALP)as a bridge between immunoassay a nd color reaction was used for catalytic hydrolysis of ascorbic acid-phosphate to generate reductive ascorbic acid.Finally,the yielded ascorbic acid could reduce silver ions to grow a silver coating on the surface of gold nanorods to generate Au@Ag NRs,which leads to the bule-shifted longitudinal absorption peak of Au NRs,accompanying with a series of perceptible color change.Under the optimal conditions,the proposed MBMCIA exhibited go od sensitivity and specificity for the detection of AFB_(1)with the detection limit as low as 5.7 pg/mL Meanwhile,the MBMCIA was also applied for the analysis of AFB_(1)in spiked wheat samples,the obtained recoveries range from 99.1%to 104.3%with relative standard deviation(RSD)less than 7.05%were acceptable.The proposed MBMCIA integrates separated,enriched,anti-interfe rence and signal read-out into one,which opens up a new avenue for an on-site visual food safety inspection or environmental monitoring.
基金supported by the National Basic Research Program of China (973 Program,No.2007CB714507)the National Natural Science Foundation of China (No.90813015)
文摘Glypican-3 （GPC3） is reported as a great promising tumor marker for hepatocellular carcinoma （HCC） diagnosis. Highly sensitive and accurate analysis of serum GPC3 （sGPC3）, in combination with or instead of traditional HCC marker alpha-fetoprotein （AFP）, is essential for early diagnosis of I-ICC. Biomaterial-functionalized magnetic particles have been utilized as solid supports with good biological compatibility for sensitive immunoassay. Here, the magnetic nanoparticles （MnPs） and magnetic microparticles （MmPs） with carboxyl groups were further modified with streptavidin, and applied for the development of chemiluminescence enzyme immunoassay （CLEIA）. After comparing between MnPs- and MmPs-based CLEIA, MnPs-based CLEIA was proved to be a better method with less assay time, greater sensitivity, better linearity and longer chemiluminescence platform. MnPs-based CLEIA was applied for detection of sGPC3 in normal liver, hepatocirrhosis, secondary liver cancer and HCC serum samples. The results indicated that sGPC3 was effective in diagnosis of HCC with high performance.
基金financially supported by the Ministry of Education and Science of the Russian Federation in the framework of increase Competitiveness Program of NUST ‘‘MISIS’’, implemented by a governmental decree dated 16th of March 2013, No. 211part of state assignment Organization of scientific researches (Project No. 16.6548.2017/BY)
文摘Lateral flow immunoassay(LFIA) is a widely used express method and offers advantages such as a short analysis time, simplicity of testing and result evaluation.However, an LFIA based on gold nanospheres lacks the desired sensitivity, thereby limiting its wide applications.In this study, spherical nanogold labels along with new types of nanogold labels such as gold nanopopcorns and nanostars were prepared, characterized, and applied for LFIA of model protein antigen procalcitonin. It was found that the label with a structure close to spherical provided more uniform distribution of specific antibodies on its surface, indicative of its suitability for this type of analysis.LFIA using gold nanopopcorns as a label allowed procalcitonin detection over a linear range of 0.5–10 ng mL^(-1) with the limit of detection of 0.1 ng mL^(-1), which was fivefold higher than the sensitivity of the assay with gold nanospheres. Another approach to improve the sensitivity of the assay included the silver enhancement method,which was used to compare the amplification of LFIA for procalcitonin detection. The sensitivity of procalcitonin determination by this method was 10 times better the sensitivity of the conventional LFIA with gold nanosphere as a label. The proposed approach of LFIA based on gold nanopopcorns improved the detection sensitivity without additional steps and prevented the increased consumption of specific reagents(antibodies).
基金supported by the National Basic Research Program of China (973 Program,no. 2007CB714507)National Nature Science Foundation of China (no. 90813015)
文摘A chemiluminescence enzyme immunoassay based on magnetic microparticles (MmPs-CLEIA) was developed to evaluate serum a-fetoprotein (AFP) in parallel with traditional colorimetric enzyme-linked immunosorbent assay (ELISA).A systematic comparison between the MmPs-CLEIA and colorimetric ELISA concluded that the MPs-CLEIA exhibited fewer dosages of immunoreagents,less total assay time,and better linearity,recovery,precision,sensitivity and validity.AFP was detected in forty human serum samples by the proposed MPs-CLEIA and ELISA,and the results were compared with commercial electrochemiluminescence immunoassay (ECLIA) kit.The correlation coefficient between MPs-CLEIA and ELISA was obtained with R 2 0.6703;however,the correlation between MPs-CLEIA and ECLIA (R 2 0.9582) was obviously better than that between colorimetric ELISA and ECLIA (R 2 0.6866).
基金supported by the National Natural Science Foundation of China(Nos.81402721,81573203,21605131)Science and Technology Department of Henan Province(No.22170004)
文摘DNA methyltransferase 1(DNMT1)is a useful biomarker for lung cancer in early clinical diagnosis.A rapid magnetic chemiluminescence immunoassay(MCLIA)for DNMT1 in human serum has been developed.Horseradish peroxidase(HRP)-second-Ab was used to labeled polyclonal antibodies of anti-DNMT1.DNMT1 in sample integrates with specific immunomagnetic beads and can constitute a supersandwiched immunoreaction.In magnetic field,nonspecific materials can be separated.After luminescent substrate luminol-H2O2-BIP was added,the relative light unit(RLU)of HRP was detected and was discovered to be directly proportional to the content of DNMT1 in sample.The correlative variables involved in the MCLIA value were optimized and the methodological evaluation was carried out.After optimization,in the range of0.5–128 ng/mL,the linear regression equation was y=0.5014 x+1.769(x was logCDNMT1,y was relative luminescence units(RLU)/RLU0),and the limit of detection was 0.01 ng/mL.The RSD of intra-and interassays were 15.8%–16.9%and 14.3%–18.1%,respectively.The recovery was from 70.0%to 106.2%.Furthermore,paralleled with purchasable enzyme-linked immunosorbent assay(ELISA)kits,MCLEIA had lower detection limit,wider linear range and shorter detection time.Therefore,the MCLEIA established in this study could be used for the sensitive detection of DNMT1 in serum sample.
基金financially supported by the Beijing Dairy Industry Innovation TeamFeed Quality and Safety Control Innovation Team of Chinese Academy of Agricultural Sciences
文摘The detection of chemical contaminants is critical to ensure dairy safety. These contaminants include veterinary medicines, antibiotics, pesticides, heavy metals, mycotoxins, and persistent organic pollutants （POPs）. Immunoassays have recently been used to detect contaminants in milk because of their simple operation, high speed, and low cost. This article describes the latest developments in the most important component of immunoassays--antibodies, and then reviews the four major substrates used for immunoassays （i.e., microplates, membranes, gels, and chips） as well as their use in the detection of milk contaminants. The paper concludes with prospects for further aDDlications of these immunoassavs.
基金supported by the national science and technology support program in the 12th Five Year Plan(2011BAK10B04 and 2011BAK10B01)the national natural science foundation of China(Grant No.31160323)the research program of the state key laboratory of food science and technology,Nanchang University(SKLF-ZZB-201306)
文摘A strip reader based lateral flow immunoassay （LFIA） was established for the rapid and quantitative detection of ractopamine （RAC） in swine urine. The ratio of the optical densities （ODs） of the test line （AT） to that of the control line （Ac） was used to effectively minimize interference among strips and sample variations. The linear range for the quantitative detection of RAC was 0.2 ng/mL to 3.5 ng/mL with a median inhibitory concentration （IC50） of 0.59＋0.06 ng/mL. The limit of detection （LOD） of the LFIA was 0.13 ng/mL. The intra-assay recovery rates were 92.97%, 97.25%, and 107.41%, whereas the inter-assay rates were 80.07%, 108.17%, and 93.7%, respectively.
