A tri-signal ultrasensitive colorimetric/electrochemical detection of ovomucoid(OM)was developed.Herein,copper oxide nanoparticles(CuO NPs)were prepared,which exhibit excellent enzyme-like activity(peroxidase-like and...A tri-signal ultrasensitive colorimetric/electrochemical detection of ovomucoid(OM)was developed.Herein,copper oxide nanoparticles(CuO NPs)were prepared,which exhibit excellent enzyme-like activity(peroxidase-like and laccase-like)and electrochemical activity.CuO@3-APBA nanoparticles(CuO@3-APBA NPs)were prepared by the coordinating Cu with the amino group on 3-aminophenobenic boric acid(3-APBA)in CuO NPs.3-APBA of CuO@3-APBA can react with diol structure on sugar chain of OM under alkaline conditions.Then,a tri-signal ultrasensitive biosensing platform for OM was established based on the catalytic activity of CuO@3-APBA nanozyme.For the first signal,CuO@3-APBA can catalyze oxidation of 1,3,5-trimethylbenzene(TMB)to turn the solution from colorless to blue in the presence of H_(2)O_(2)(absorbance at 652 nm).For the second signal,CuO@3-APBA can catalyze the oxidation of substrates(2,4-dichlorophenol and 4-aminoantipyrine)and turn the solution from colorless to pink(absorbance at 510 nm).For the third signal,electrochemical oxidation peak of copper ion from Cu^(+)to Cu^(2+)of Cu O@3-APBA was recorded by differential pulse voltammetry,which was used to determine the OM.The sensing platform exhibited a wide linear range(0.0000316-100.000000 ng/mL)with a low detection limit(0.0105 pg/mL),as well as showed advantages,such as satisfactory reproducibility,good stability,and excellent selectivity.The assay has the potential applications for ultrasensitive detection of allergen in foods.展开更多
Chymosin is one of the critical enzymes in cheese making.Herein,we proposed a novel fluorometric assay for chymosin determination.Firstly,covalent organic frameworks(COF)were synthesized and exfoliated to 2-dimensiona...Chymosin is one of the critical enzymes in cheese making.Herein,we proposed a novel fluorometric assay for chymosin determination.Firstly,covalent organic frameworks(COF)were synthesized and exfoliated to 2-dimensional COF nanosheets(COF NS)by ultrasound treatment.Gold nanoparticles(Au NPs)were loaded with COF NS to prepare AuNPs/COF NS(Au@COF NS).Secondly,rhodamine B(RhB)modified substrate peptide(Pep)for chymosin was linked with Au@COF NS to construct a Pep-Au@COF NS nanocomposite.For the sensing principle,fluorescence of RhB was quenched by Au@COF NS and the fluorescence intensity was weak due to the fluorescence resonance energy transfer between COF NS and RhB of Pep.However,in the presence of chymosin,the RhB was released by specific cleavage of the substrate peptide by chymosin and resulted in the recovery of fluorescence.The increased fluorescence intensity was proportional to the increase of chymosin concentration and thus a“turn on”fluorescent sensor for chymosin was constructed.The sensor showed a linear range in the concentration of 0.05-60.00μg/mL for the detection of chymosin with a detection limit of 20 ng/mL.The sensor was used to quantify chymosin in rennet product with good selectivity,which has the potential applications in cheese manufacturing.展开更多
Circulating tumor cells(CTCs)are important markers for cancer.The part of tumor cells that are detached from the primary tumor or metastatic tumor and enter the blood circulation is called CTCs.It is crucial to develo...Circulating tumor cells(CTCs)are important markers for cancer.The part of tumor cells that are detached from the primary tumor or metastatic tumor and enter the blood circulation is called CTCs.It is crucial to develop a rapid,accurate,and easy-to-implement diagnostic system for CTCs for early tumor diagnosis and for monitoring progression of the disease.In this work,we reported a colorimetric and fluorescent dual-mode assay for the detection of CTCs.Our assay used magnetic nanoparticles and aptamer for CTCs capture and gold nanoparticles-loaded covalent organic frameworks(Au@COFs)for signal amplification,respectively.The magnetic nanoparticles were modified with folic acid to capture CTCs by interaction between folic acid and the folate receptor overexpressed on the surface of tumor cells.The covalent organic frameworks were engineered to have both nitro-reductase-like and glucose–oxidase-like activities.The nitro-reductase-like activity converted the substrate p-nitrophenol to p-nitroaniline for colorimetric detection,and the glucose-oxidase-like activity enabled fluorescence detection.Specifically,Au@COFs catalyzed glucose oxidation and generated hydrogen peroxide to oxidize Fe 2+to Fe 3+,which converted MIL(Al)-MOF to MIL(Fe)-MOF through ion exchange,resulting in the fluorescence quenching of MIL(Al)-MOF.Our assay showed high sensitivity with a detection limit of 17 cells/mL using MCF-7 cells as model cancer cells.This work provided an e fficient and ultrasensitive strategy for CTCs detection and has potential applications in cancer identification and diagnosis.Dual-mode detection system,combining colorimetric and fluorescent signals,integration of magnetic nanoparticles and aptamers for CTC capture,and utilization of covalent organic frameworks loaded with gold nanoparticles for signal amplification can improve sensitivity and accuracy.展开更多
基金financially supported by Major Science and Technology Project of Yunnan Province(202302AE090022)the National Natural Science Foundation of China(21764005,32160236)+4 种基金National Key Research and Development Program of China(2022YFC2601604)Spring City Plan:the High-level Talent Promotion and Training Project of Kunming(2022SCP001)the Second Phase of“Double-First Class”Program Construction of Yunnan UniversityProgram for Donglu Scholars of Yunnan Universitythe Research Innovation Fund for Graduate Students of School of Chemical Science and Technology,Yunnan University。
文摘A tri-signal ultrasensitive colorimetric/electrochemical detection of ovomucoid(OM)was developed.Herein,copper oxide nanoparticles(CuO NPs)were prepared,which exhibit excellent enzyme-like activity(peroxidase-like and laccase-like)and electrochemical activity.CuO@3-APBA nanoparticles(CuO@3-APBA NPs)were prepared by the coordinating Cu with the amino group on 3-aminophenobenic boric acid(3-APBA)in CuO NPs.3-APBA of CuO@3-APBA can react with diol structure on sugar chain of OM under alkaline conditions.Then,a tri-signal ultrasensitive biosensing platform for OM was established based on the catalytic activity of CuO@3-APBA nanozyme.For the first signal,CuO@3-APBA can catalyze oxidation of 1,3,5-trimethylbenzene(TMB)to turn the solution from colorless to blue in the presence of H_(2)O_(2)(absorbance at 652 nm).For the second signal,CuO@3-APBA can catalyze the oxidation of substrates(2,4-dichlorophenol and 4-aminoantipyrine)and turn the solution from colorless to pink(absorbance at 510 nm).For the third signal,electrochemical oxidation peak of copper ion from Cu^(+)to Cu^(2+)of Cu O@3-APBA was recorded by differential pulse voltammetry,which was used to determine the OM.The sensing platform exhibited a wide linear range(0.0000316-100.000000 ng/mL)with a low detection limit(0.0105 pg/mL),as well as showed advantages,such as satisfactory reproducibility,good stability,and excellent selectivity.The assay has the potential applications for ultrasensitive detection of allergen in foods.
基金supported by Major Science and Technology Project of Yunnan Province(202302AE090022)Key Research and Development Program of Yunnan(202203AC100010)+4 种基金the National Natural Science Foundation of China(32160597,32160236,32371463)National Key Research and Development Program of China(2022YFC2601604)Cardiovascular Ultrasound Innovation Team of Yunnan Province(202305AS350021)Spring City Plan:the High-Level Talent Promotion and Training Project of Kunming(2022SCP001)Graduate Tutor Team of Yunnan Province,and the Second Phase of"Double-First Class"Program Construction of Yunnan University.
文摘Chymosin is one of the critical enzymes in cheese making.Herein,we proposed a novel fluorometric assay for chymosin determination.Firstly,covalent organic frameworks(COF)were synthesized and exfoliated to 2-dimensional COF nanosheets(COF NS)by ultrasound treatment.Gold nanoparticles(Au NPs)were loaded with COF NS to prepare AuNPs/COF NS(Au@COF NS).Secondly,rhodamine B(RhB)modified substrate peptide(Pep)for chymosin was linked with Au@COF NS to construct a Pep-Au@COF NS nanocomposite.For the sensing principle,fluorescence of RhB was quenched by Au@COF NS and the fluorescence intensity was weak due to the fluorescence resonance energy transfer between COF NS and RhB of Pep.However,in the presence of chymosin,the RhB was released by specific cleavage of the substrate peptide by chymosin and resulted in the recovery of fluorescence.The increased fluorescence intensity was proportional to the increase of chymosin concentration and thus a“turn on”fluorescent sensor for chymosin was constructed.The sensor showed a linear range in the concentration of 0.05-60.00μg/mL for the detection of chymosin with a detection limit of 20 ng/mL.The sensor was used to quantify chymosin in rennet product with good selectivity,which has the potential applications in cheese manufacturing.
基金financially supported by Major science and technology project of Yunnan Province(202302AE090022)Key Research and Development Program of Yunnan(202203AC100010)+6 种基金the National Natural Science Foundation of China(32160597,32160236,32371463)National Key Research and Development Program of China(2022YFC2601604)Cardiovascular Ultrasound Innovation Team of Yunnan Province(202305AS350021)Spring City Plan:the High-level Talent Promotion and Training Project of Kunming(2022SCP001)the Association Foundation Program of Yunnan Provincial Science and TechnologyDepar tmentKunming Medical University(202101AY070001-278)the second phase of“Double-First Class”program construction of Yunnan University。
文摘Circulating tumor cells(CTCs)are important markers for cancer.The part of tumor cells that are detached from the primary tumor or metastatic tumor and enter the blood circulation is called CTCs.It is crucial to develop a rapid,accurate,and easy-to-implement diagnostic system for CTCs for early tumor diagnosis and for monitoring progression of the disease.In this work,we reported a colorimetric and fluorescent dual-mode assay for the detection of CTCs.Our assay used magnetic nanoparticles and aptamer for CTCs capture and gold nanoparticles-loaded covalent organic frameworks(Au@COFs)for signal amplification,respectively.The magnetic nanoparticles were modified with folic acid to capture CTCs by interaction between folic acid and the folate receptor overexpressed on the surface of tumor cells.The covalent organic frameworks were engineered to have both nitro-reductase-like and glucose–oxidase-like activities.The nitro-reductase-like activity converted the substrate p-nitrophenol to p-nitroaniline for colorimetric detection,and the glucose-oxidase-like activity enabled fluorescence detection.Specifically,Au@COFs catalyzed glucose oxidation and generated hydrogen peroxide to oxidize Fe 2+to Fe 3+,which converted MIL(Al)-MOF to MIL(Fe)-MOF through ion exchange,resulting in the fluorescence quenching of MIL(Al)-MOF.Our assay showed high sensitivity with a detection limit of 17 cells/mL using MCF-7 cells as model cancer cells.This work provided an e fficient and ultrasensitive strategy for CTCs detection and has potential applications in cancer identification and diagnosis.Dual-mode detection system,combining colorimetric and fluorescent signals,integration of magnetic nanoparticles and aptamers for CTC capture,and utilization of covalent organic frameworks loaded with gold nanoparticles for signal amplification can improve sensitivity and accuracy.
