Remote tracking the variation of air quality in an effective way will be highly helpful to decrease the health risk of human short-and long-term exposures to air pollution.However,high power consumption and poor sensi...Remote tracking the variation of air quality in an effective way will be highly helpful to decrease the health risk of human short-and long-term exposures to air pollution.However,high power consumption and poor sensing performance remain the concerned issues,thereby limiting the scale-up in deploying air quality tracking networks.Herein,we report a standalone-like smart device that can remotely track the variation of air pollutants in a power-saving way.Brevity,the created smart device demonstrated satisfactory selectivity(against six kinds of representative exhaust gases or air pollutants),desirable response magnitude(164–100 ppm),and acceptable response/recovery rate(52.0/50.5 s),as well as linear response relationship to NO2.After aging for 2 weeks,the created device exhibited relatively stable sensing performance more than 3 months.Moreover,a photoluminescence-enhanced light fidelity(Li-Fi)telecommunication technique is proposed and the Li-Fi communication distance is significantly extended.Conclusively,our reported standalone-like smart device would sever as a powerful sensing platform to construct high-performance and low-power consumption air quality wireless sensor networks and to prevent air pollutant-induced diseases via a more effective and low-cost approach.展开更多
Oxidizing CIO^(-)and IO_(4)^(-)exist widely in environment and are closely related to the health of organisms.Accordingly,fast,sensitive,and direct detection of the two species is significant.Using IFE in UCNPs@PAA an...Oxidizing CIO^(-)and IO_(4)^(-)exist widely in environment and are closely related to the health of organisms.Accordingly,fast,sensitive,and direct detection of the two species is significant.Using IFE in UCNPs@PAA and Fe(Ⅱ)-phenanthroline system,an elegant ratiometric fluorescent nanosensor,without noble metal nanoparticle,was designed for the detection of CIO-and IO4-.Fe(Ⅱ)-phenanthroline complex is used as fluorescent absorber,which can quench green light of UCNPs with gradually varied extent depending on the concentration of Fe(Ⅱ).The linear zone extends to 800 and 120μmol/L while the detection limit is 1.30 and 0.58μmol/L for NaCIO and NaIO_(4),respectively.Finally,the nanosensor was successfully applied to detect NaCIO and NaIO4spiked in milk,spring water,and tap water with good recoveries.展开更多
The global propagation of environmental biocontaminants such as antibiotic resistant pathogens and their antibiotic resistance genes（ARGs） is a public health concern that highlights the need for improved monitoring ...The global propagation of environmental biocontaminants such as antibiotic resistant pathogens and their antibiotic resistance genes（ARGs） is a public health concern that highlights the need for improved monitoring strategies. Here, we demonstrate the environmental stability and applicability of an oligonucleotide-functionalized gold nanosensor. The mec A ARG was targeted as model biocontaminant due to its presence in clinically-relevant pathogens and to its emergence as an environmental contaminant.mec A-specific nanosensors were tested for antibiotic resistance gene（ARG） detection in ARG-spiked effluent from four wastewater treatment plants（WWTPs）. The mec A-specific nanosensors showed stability in environmental conditions and in high ionic strength（[MgCl_2] 〈 50 m M）, and high selectivity against mismatched targets. Spectrophotometric detection was reproducible with an LOD of 70 pM（≈ 4 × 10~7 genes/μL）, even in the presence of interferences associated with non-target genomic DNA and complex WWTP effluent. This contribution supports the environmental applicability of a new line of cost-effective, field-deployable tools needed for wide-scale biocontaminant monitoring.展开更多
In this study, we designed and applied proteinmimicking nanoparticles(Protmin) as an intracellular nanosensor for in vivo detection of lead ions(Pb^(2+)).Monodispersed gold nanoparticles(Au NPs) of 13 nm in diameter w...In this study, we designed and applied proteinmimicking nanoparticles(Protmin) as an intracellular nanosensor for in vivo detection of lead ions(Pb^(2+)).Monodispersed gold nanoparticles(Au NPs) of 13 nm in diameter were modified using poly-adenine-tailed Pb^(2+)-specific 8–17 DNAzyme to form a spherical and functional Protmin. Substrate strands modified with a fluorophore at the 50 end and a quencher at the 30 end were bound to DNAzyme. Pb^(2+) facilitated cleavage of DNAzyme to release the fluorophore-modified short strands to generate fluorescence. We observed rapid kinetics of the Protmin nanosensor, for which the typical assay time was 10 min.Further, we demonstrated the Protmin nanosensor could readily enter living cells and respond to Pb^(2+) in the intracellular environment. The broad of range of Protmindesigns will be useful for advancing biological and medical applications.展开更多
We report a novel technique to enhance the ultraviolet （UV） photosensitivity of a ZnO nanosensor with ZnO nanowires bridged on micromachined metallic electrodes. The experimental results reveal that the photoconduct...We report a novel technique to enhance the ultraviolet （UV） photosensitivity of a ZnO nanosensor with ZnO nanowires bridged on micromachined metallic electrodes. The experimental results reveal that the photoconductivity and the time response of the ZnO nanowire sensor with either Schottky or Ohmic contacts are significantly improved by electrifying the nanowire sensors using an alternating current at the frequency of megahertz. An integrated UV sensor incorporating ZnO nanowires with a constant current mode driving circuit is developed, which demonstrates promising sensitivity and time response to UV illumination with a low power consumption.展开更多
The cytoprotective messenger nitric oxide (NO) and cytotoxic peroxynitrite (ONOO-) are the main components of oxidative stress and can be generated by endothelial cells. A tandem of electrochemical nanosensors (diamet...The cytoprotective messenger nitric oxide (NO) and cytotoxic peroxynitrite (ONOO-) are the main components of oxidative stress and can be generated by endothelial cells. A tandem of electrochemical nanosensors (diameter 200-300 nm) were used to measure, in situ, the balance between NO and ONOO-produced by human umbilical vein endothelial cells (HUVEC’s). The amperometric nanosensors were placed 5 ± 2 μm from the surface of the endothelial cells and the concentration of NO and ONOO- was measured at 630 mV and -300 mV (vs Ag/AgCl) respectively. Normal, functional, endothelial cells produced maximal 450 ± 25 nmol.L-1 of NO and 180 ± 15 nmol.L-1 of ONOO- in about 3 s, after stimulation with calcium ionophore. The in situ measurements of NO and ONOO- were validated using nitric oxide synthase inhibitor L-NMMA, ONOO- scavenger Mn(III) porphyrin, and superoxide dismutase (PEG-SOD). The ratio of NO concentration to ONOO- concentration ([NO]/[ONOO-]) was introduced for quantification of both, the redox balance and the level of the nitroxidative stress in the endothelium. [NO]/[ONOO-] was 2.7 ± 0.1 in a functional endothelium. The model of the dysfunctional endothelium was made by the treatment of HUVEC’s with angiotensin II for 20 min. Dysfunctional HUVEC’s produced only 115 ± 15 nmol.L-1 of NO, but generated a significantly higher concentration of ONOO- of 490 ± 30 nmol.L-1. The [NO]/[ONOO-] ratio decreased to 0.23 ± 0.14 in the dysfunctional endothelium. Electrochemical nanosensors can be effectively used for in situ monitoring of changing levels of nitroxidative/ oxidative stress, and may be useful in early medical diagnosis of the cardiovascular system.展开更多
Ratiometric fluorescent detection of iron(Ⅲ)(Fe^(3+))offers inherent self-calibration and contactless analytic capabilities.However,realizing a dual-emission near-infrared(NIR)nanosensor with a low limit of detection...Ratiometric fluorescent detection of iron(Ⅲ)(Fe^(3+))offers inherent self-calibration and contactless analytic capabilities.However,realizing a dual-emission near-infrared(NIR)nanosensor with a low limit of detection(LOD)is rather challenging.In this work,we report the synthesis of water-dispersible erbium-hyperdoped silicon quantum dots(Si QDs:Er),which emit NIR light at the wavelengths of 810 and 1540 nm.A dual-emission NIR nanosensor based on water-dispersible Si QDs:Er enables ratiometric Fe^(3+)detection with a very low LOD(0.06μM).The effects of pH,recyclability,and the interplay between static and dynamic quenching mechanisms for Fe^(3+)detection have been systematically studied.In addition,we demonstrate that the nanosensor may be used to construct a sequential logic circuit with memory functions.展开更多
A new fluorescence silver nanosensor assisted by surfactant has been recently synthesized and applied to ultra trace nickel determination. The methodology was validated by the standard addition method and satisfactori...A new fluorescence silver nanosensor assisted by surfactant has been recently synthesized and applied to ultra trace nickel determination. The methodology was validated by the standard addition method and satisfactorily applied to nickel determination in urine without previous treatment, coming from subjects with different smoking addiction levels and second hand smokers. Within-day precision was better than 0.011 CV. The reproducibility （between-days precision） was also evaluated over 3 days by performing six determinations each day with a CV of 0.025. The proposed methodology represents a promising approach in the area of biological monitoring due to its low operation cost, simplicity of instrumentation, high sampling speed and non-polluting solvents. Obtained results of urinary nickel concentration were successfully correlated with the tobacco addiction.展开更多
A new fluorescence silver nanosensor assisted by surfactant has been synthesized and applied to ultra trace nickel determination. Operational variables which influence nanomaterial synthesis have been studied and opti...A new fluorescence silver nanosensor assisted by surfactant has been synthesized and applied to ultra trace nickel determination. Operational variables which influence nanomaterial synthesis have been studied and optimized. Synthesis was very fast and simple using non polluting solvents; silver chemical reduction was carried out at room temperature. Spectroscopic studies were carried out in order to assure the uniformed of nanomaterial obtained. Fluorescent signal of silver nanoparticles resulted enhanced in presence of Ni（II）. At optimal experimental conditions, a detection limit of 0.036 pg＇L1 and quantification limit 0.12 pg＇L~ were obtained. The calibration sensitivity was 2 x 1014 L.pg-l.cm1 for the new methodology, with a range of linearity of six orders of magnitude between 0.12 and 2.93 × 10^5 pg L^-1. The tolerance levels for potential interferent ions were studied with good results. The proposed methodology represents a promising approach for Ni（II） traces quantification due to its low operation cost, simplicity of instrumentation, high sampling speed and non-polluting solvents.展开更多
Bio-nanosensors(Bio-NSs)have attracted much attention recently due to their unique properties.Among all of the bio-NSs,the intracellular proton sensor is significant for biomedicine studies and clinic diagnosis.Proton...Bio-nanosensors(Bio-NSs)have attracted much attention recently due to their unique properties.Among all of the bio-NSs,the intracellular proton sensor is significant for biomedicine studies and clinic diagnosis.Proton nanosensors(PNSs)with different pH sensitive ranges could satisfy different research requirements.Here we report a facile method to build a PNS with a neutral to basic pH sensitive range,in which the commercial pH indicator,fluoresceinamine(FA),was covalently coupled to the carboxylic-rich amphiphilic polymer(AP)coated gold nanoparticles(AuNPs).展开更多
Rapid and accurate diagnosis of oral cancer aggressiveness is associated with preoperative guidance and postoperative treatment.However,traditional diagnostic methods are time-consuming and easily misdiagnosed,which m...Rapid and accurate diagnosis of oral cancer aggressiveness is associated with preoperative guidance and postoperative treatment.However,traditional diagnostic methods are time-consuming and easily misdiagnosed,which makes it challenging to achieve high-precision classification.Herein,we introduce a recognition engineering-mediated multichannel nanosensor for the analysis of tumor metabolites,allowing for sensitive and rapid in vitro and intraoperative cancer malignancy discrimination.This nanosensor system utilizes engineered carbon dots(CDs)with various ratios of amino and carboxyl functional groups,assembled as a“shell”on gold nanoparticles(AuNPs).The multichannel nanosensor displayed distinct fingerprint patterns for fourteen tumor metabolites such as amino acids,nucleic acids,and other metabolites.It offers rapid“turn-on”fluorescence-encoded profiling,generating unique signatures for cancer malignancy within 15 min.The nanosensor demonstrated 100%accuracy in identifying the oral squamous cell carcinoma(OSCC)subtype and assessing malignancy levels.It will provide detailed pathology for the identification of clinical cancer tissue samples,including cancer cell subtype and differentiation grade.Together,our study highlights the potential of the fluorescent-encoded multichannel nanosensor as a powerful in vitro and intraoperative diagnostic tool for cancer malignancy and treatment guidance in advanced clinical oncology.展开更多
Stevia crystal can be defined as a botanical herb that has good properties to use as a substitute for sugar.The electrochemical study has been utilized for the purpose of calculating the limited dosage of the safety t...Stevia crystal can be defined as a botanical herb that has good properties to use as a substitute for sugar.The electrochemical study has been utilized for the purpose of calculating the limited dosage of the safety that should be used in black tea by cyclic voltammetry(CV)technique using the nanosensor as a more effective glassy carbon electrode(GCE)and carbon nanotubes(CNTs).Stevia’s oxidation current peak has been 400 mV at 0.40 mmol/L concentration(i.e.28 mg/mL),and reduction current peaks at 600 and–600 mV.It leads to the conclusion that stevia is a limited concentration antioxidant component safe for use in black tea.Additionally,electro-chemical characteristics of the stevia compound in the black tea have been investigated at alkaline and acidic pH in order to give oxidizing behaviors in the alkaline medium,while in an acidic medium as an antioxidant agent in black tea.Other chemical properties such as different scan rates,reliability,and stability have also been investigated.展开更多
In this paper,the relationship of intracellular acidification and apoptosis in Hela cells induced by vin-cristine sulfate has been studied by use of the ratiometric pH nanosensors that have been developed by our group...In this paper,the relationship of intracellular acidification and apoptosis in Hela cells induced by vin-cristine sulfate has been studied by use of the ratiometric pH nanosensors that have been developed by our group,employing fluorescein isothiocyanate(FITC) doped as the pH-sensitive dye and Tris(2,2'-bipyidyl) dichlororuthenium(II) hexahydrate(RuBpy) doped as reference dye. The pH change of the Hela cells induced by vincristine sulfate has been monitored in vivo,in situ and real time by use of the ratiometric pH nanosensors. The experimental results show that the pH of the apoptotic Hela cells induced by vincristine sulfate has been acidified from 7.11 to 6.51,and the percentage of intra-cellular acidification is correlated with the induced concentration and incubation time of the vincristine sulfate. The further study of the percentage of intracellular acidification and the percentage of apop-tosis of Hela cells at the same time reveals that apoptosis of Hela cells induced by vincristine sulfate is preceded by intracellular acidification. These results would provide theoretical foundation for the therapy of cancer through interfering the pH of cells by use of vincristine sulfate or other anti-cancer drugs.展开更多
Applications based on silicene as grown on substrates are of high interest toward actual utilization of this unique material. Here we explore, from first principles, the nature of carbon monoxide adsorption on semicon...Applications based on silicene as grown on substrates are of high interest toward actual utilization of this unique material. Here we explore, from first principles, the nature of carbon monoxide adsorption on semiconducting silicene nanoribbons and the resulting quantum conduction modulation with and without silver contacts for sensing applications. We find that quantum conduction is detectably modified by weak chemisorption of a single CO molecule on a pristine silicene nanoribbon. This modification can be attributed to the charge transfer from CO to the silicene nanoribbon and the deformation induced by the CO chemisorption. Moderate binding energies provide an optimal mix of high detectability and recoverability. With Ag contacts attached to a -1 nm silicene nanoribbon, the interface states mask the conductance modulations caused by CO adsorption, emphasizing length effects for sensor applications. The effects of atmospheric gases--nitrogen, oxygen, carbon dioxide, and water--as well as CO adsorption density and edge-dangling bond defects, on sensor functionality are also investigated. Our results reveal pristine silicene nanoribbons as a promising new sensing material with single molecule resolution.展开更多
Water pollution accidents, such as the Flint water crisis in the United States, caused by lead contamination have raised concern on the safety of drinking water distribution systems. Thus, the routine monitoring of le...Water pollution accidents, such as the Flint water crisis in the United States, caused by lead contamination have raised concern on the safety of drinking water distribution systems. Thus, the routine monitoring of lead in water is highly required and demands efficient, sensitive, cost-effective, and reliable lead detection methods. This study reports a label-free colorimetric nanosensor that uses unmodified gold nanoparticles (AuNPs) as indicators to enable rapid and ultra-sensitive detection of lead in environmental water. The 8-17 DNAzyme was truncated in this study to facilitate the detachment of single-stranded DNA fragments after substrate cleavage in the presence of Pb「. The detached fragments were adsorbed over AuNPs and protected against salt concentration-induced aggregation. Accordingly, high Pb^2+ would result in rapid color change from blue to pink. The established sensing principle achieved a sensitive limit of detection of 0.2×10^-9mol/L Pb^2+. with a linear working range of two orders of magnitude from 0.5×10^-9mol/L to 5×10^-9mol/L. The selectivity of the nanosensor was demonstrated by evaluating the interfering metal ions. The developed nanosensor can serve as a substitute for the rapid analysis and monitoring of trace lead levels under the drinking water distribution system and even other environmental water samples.展开更多
Although nanotechnology has led to important advances in in vitro diagnostics, the development of nanosensors for in vivo detection remains very challenging. Here, we demonstrated the proof-of-principle of in vivo det...Although nanotechnology has led to important advances in in vitro diagnostics, the development of nanosensors for in vivo detection remains very challenging. Here, we demonstrated the proof-of-principle of in vivo detection of nudeic acid targets using a promising type of surface-enhanced Raman scattering （SERS） nanosensor implanted in the skin of a large animal model （pig）. The in vivo nanosensor used in this study involves the ＂inverse molecular sentinel＂ detection scheme using plasmonics-active nanostars, which have tunable absorption bands in the near infrared region of the ＂tissue optical window＂, rendering them efficient as an optical sensing platform for in vivo optical detection. Ex vivo measurements were also performed using human skin grafts to demonstrate the detection of SERS nanosensors through tissue. In this stud, a new core--shell nanorattle probe with Raman reporters trapped between the core and shell was utilized as an internal standard system for self-calibration. These results illustrate the usefulness and translational potential of the SERS nanosensor for in vivo biosensing.展开更多
Compared with conventional water-soluble fluorescence probes,pH-sensitive fluorescent nanosensors based on hydrophobic indicators remain largely unexplored.We report here the unique pH response of the nanosensors with...Compared with conventional water-soluble fluorescence probes,pH-sensitive fluorescent nanosensors based on hydrophobic indicators remain largely unexplored.We report here the unique pH response of the nanosensors with a hydrophobic indicator(Ch3,a Nile Blue derivative)in polymeric nanoparticles(NPs).At the aqueous-organic interface of the NPs,spectral overlap and dye accumulation caused significant Förster resonance energy transfer(FRET)not only between the protonated and deprotonated Ch3(hetero-FRET),but also between the protonated and deprotonated Ch3 themselves(homo-FRET).The pH response was simulated according to an interfacial response mechanism and the dynamic range was found to depend on the size of the NPs and dye distribution(Kp).Therefore,adjusting the size of the NPs and the local dye concentration gave rise to a series of dynamic sensing ranges with apparent pKa values from 2.7 to 9.6 based on a single indicator.The nanosensors were successfully delivered to HeLa cells to monitor subcellular pH values in the endosomes and lysosomes.Based on cellular calibrations,the average pH in the organelles were determined to be ca.4.7.Moreover,the pH neutralization process during lysosome membrane permeabilization(LMP)induced by hydrogen peroxide stimulation was also successfully visualized with the nanosensors.展开更多
A general stepwise strategy for the preparation of new humidity-responsive plasmonic nanosensor was described for the first time, based on Ag film functionalization by polyacrylamide（PAAM） brushes via surface-initia...A general stepwise strategy for the preparation of new humidity-responsive plasmonic nanosensor was described for the first time, based on Ag film functionalization by polyacrylamide（PAAM） brushes via surface-initiated atom transfer radical polymerization（SI-ATRP） method and then assembled with gold nanoparticles（Au NPs）. We designed by this way a new plasmonic device made of Au NPs embedded in a humid vapor responsive polymer layer on Ag film and extensively characterized by surface-enhanced Raman scattering（SERS）. When the relative humidity（RH） is above 50%, the number of plasmonic hotspots decreases, causing SERS signal reduced noticeably, for the volume expansion of PAAM brushes varied the nano-gap between closely spaced Au NPs, and between Au NPs and Ag film. The reversible optical properties of the prepared nanocomposite tuned by RH were probed through SERS using 4-mercaptopyridine（4-Mpy） as a molecular probe, and the decrease of the RH reversibly induces a significant enhancement of the 4-Mpy SERS signal. By means of the high reversibility, the RH responsive nanocomposite developed in this paper provides a dynamic SERS platform and can be applied as plasmonic nanosensor which is proved to be stable for at least two months.展开更多
Intracellular potassium ions(K^(+))play pivotal roles in many physiological processes.Several K^(+)sensors have been developed for probing cellular K^(+)fluctuations.Nevertheless,the existing solutions are incompatibl...Intracellular potassium ions(K^(+))play pivotal roles in many physiological processes.Several K^(+)sensors have been developed for probing cellular K^(+)fluctuations.Nevertheless,the existing solutions are incompatible and impractical for intracellular K^(+)probing.Herein,we report a supersmall biomimetic K^(+)nanosensor to serve as a transmembrane vector capable of electrochemically detecting intracellular K^(+)in a minimally invasive manner.展开更多
This work focuses on the fabrication and characterization of Chemical Field-Effect Transistor(ChemFET)gas nanosensor arrays based on single nanowire(SNW).The fabrication processes include micro and nanofabrication tec...This work focuses on the fabrication and characterization of Chemical Field-Effect Transistor(ChemFET)gas nanosensor arrays based on single nanowire(SNW).The fabrication processes include micro and nanofabrication techniques enabled by a combination of ultraviolet(UV)and e-beam lithography to build the ChemFET structure.Results show the integration and connection of SNWs across the multiple pairs of nanoelectrodes in the ChemFET by dielectrophoresis process(DEP)thanks to the incorporation of alignment windows(200-300 nm)adapted to the diameter of the NWs.Measurements of the SNW ChemFET array's output and transfer characteristics prove the influence of gate bias on the drain current regulation.Tests upon hydrogen(H_(2))and nitrogen dioxide(NO_(2))as analyte models of reducing and oxidizing gases show the ChemFET sensing functionality.Moreover,results demonstrate better response characteristics to H_(2)when the ChemFET operates in the subthreshold regime.The design concepts and methods proposed for fabricating the SNW-based ChemFET arrays are versatile,reproducible,and most likely adaptable to other systems where SNW arrays are required.展开更多
基金the financial support for this research from the National Key Research and Development Program of China(Grant No.2017YFA0205301)National Natural Science Foundation of China(Grant No.61771267,61774106)+6 种基金Oceanic Interdisciplinary Program of Shanghai Jiao Tong University(Grant No.BX2020208)Shanghai Natural Science Foundation(Grant No.86973)Natural Science Foundation of Ningbo City(Grant No.2017A610229)National Postdoctoral Program for Innovative Talents(Grant No.BX20190205)Special fund for science and technology innovation of Shanghai Jiao Tong University(Grant No.YG2017MS70)Shanghai Municipal Bureau of Economy and Information Technology(Grant No.XC-ZXSJ-02-2016-05)China Postdoctoral Science Foundation.
文摘Remote tracking the variation of air quality in an effective way will be highly helpful to decrease the health risk of human short-and long-term exposures to air pollution.However,high power consumption and poor sensing performance remain the concerned issues,thereby limiting the scale-up in deploying air quality tracking networks.Herein,we report a standalone-like smart device that can remotely track the variation of air pollutants in a power-saving way.Brevity,the created smart device demonstrated satisfactory selectivity(against six kinds of representative exhaust gases or air pollutants),desirable response magnitude(164–100 ppm),and acceptable response/recovery rate(52.0/50.5 s),as well as linear response relationship to NO2.After aging for 2 weeks,the created device exhibited relatively stable sensing performance more than 3 months.Moreover,a photoluminescence-enhanced light fidelity(Li-Fi)telecommunication technique is proposed and the Li-Fi communication distance is significantly extended.Conclusively,our reported standalone-like smart device would sever as a powerful sensing platform to construct high-performance and low-power consumption air quality wireless sensor networks and to prevent air pollutant-induced diseases via a more effective and low-cost approach.
基金Project supported by the Natural Science Foundation of Shandong Province(ZR2016EMM20,ZR2019PEM012)National Natural Science Foundation of China(21808114)the Foundation(ZZ20190310)of State Key Laboratory of Biobased Material and Green Papermaking。
文摘Oxidizing CIO^(-)and IO_(4)^(-)exist widely in environment and are closely related to the health of organisms.Accordingly,fast,sensitive,and direct detection of the two species is significant.Using IFE in UCNPs@PAA and Fe(Ⅱ)-phenanthroline system,an elegant ratiometric fluorescent nanosensor,without noble metal nanoparticle,was designed for the detection of CIO-and IO4-.Fe(Ⅱ)-phenanthroline complex is used as fluorescent absorber,which can quench green light of UCNPs with gradually varied extent depending on the concentration of Fe(Ⅱ).The linear zone extends to 800 and 120μmol/L while the detection limit is 1.30 and 0.58μmol/L for NaCIO and NaIO_(4),respectively.Finally,the nanosensor was successfully applied to detect NaCIO and NaIO4spiked in milk,spring water,and tap water with good recoveries.
基金supported by US National Science Foundation grants CBET-1133746 and OISE-1545756support for MVR was provided by the Virginia Tech Graduate School
文摘The global propagation of environmental biocontaminants such as antibiotic resistant pathogens and their antibiotic resistance genes（ARGs） is a public health concern that highlights the need for improved monitoring strategies. Here, we demonstrate the environmental stability and applicability of an oligonucleotide-functionalized gold nanosensor. The mec A ARG was targeted as model biocontaminant due to its presence in clinically-relevant pathogens and to its emergence as an environmental contaminant.mec A-specific nanosensors were tested for antibiotic resistance gene（ARG） detection in ARG-spiked effluent from four wastewater treatment plants（WWTPs）. The mec A-specific nanosensors showed stability in environmental conditions and in high ionic strength（[MgCl_2] 〈 50 m M）, and high selectivity against mismatched targets. Spectrophotometric detection was reproducible with an LOD of 70 pM（≈ 4 × 10~7 genes/μL）, even in the presence of interferences associated with non-target genomic DNA and complex WWTP effluent. This contribution supports the environmental applicability of a new line of cost-effective, field-deployable tools needed for wide-scale biocontaminant monitoring.
基金supported by the National Natural Science Foundation of China(Nos.21390414 and 21605087)the Chinese Academy of Sciences(No.QYZDJ-SSW-SLH031)+2 种基金the China Postdoctoral Science Foundation funded project(No.BX201700123)the Scientific Research Foundation of Nanjing University of Posts and Telecommunications(No.NY215058)the Natural Science Fund for Colleges and Universities in Jiangsu Province(16KJB150032)
文摘In this study, we designed and applied proteinmimicking nanoparticles(Protmin) as an intracellular nanosensor for in vivo detection of lead ions(Pb^(2+)).Monodispersed gold nanoparticles(Au NPs) of 13 nm in diameter were modified using poly-adenine-tailed Pb^(2+)-specific 8–17 DNAzyme to form a spherical and functional Protmin. Substrate strands modified with a fluorophore at the 50 end and a quencher at the 30 end were bound to DNAzyme. Pb^(2+) facilitated cleavage of DNAzyme to release the fluorophore-modified short strands to generate fluorescence. We observed rapid kinetics of the Protmin nanosensor, for which the typical assay time was 10 min.Further, we demonstrated the Protmin nanosensor could readily enter living cells and respond to Pb^(2+) in the intracellular environment. The broad of range of Protmindesigns will be useful for advancing biological and medical applications.
基金Project supported by the National Natural Science Foundation of China (Grant No. 91123017)
文摘We report a novel technique to enhance the ultraviolet （UV） photosensitivity of a ZnO nanosensor with ZnO nanowires bridged on micromachined metallic electrodes. The experimental results reveal that the photoconductivity and the time response of the ZnO nanowire sensor with either Schottky or Ohmic contacts are significantly improved by electrifying the nanowire sensors using an alternating current at the frequency of megahertz. An integrated UV sensor incorporating ZnO nanowires with a constant current mode driving circuit is developed, which demonstrates promising sensitivity and time response to UV illumination with a low power consumption.
文摘The cytoprotective messenger nitric oxide (NO) and cytotoxic peroxynitrite (ONOO-) are the main components of oxidative stress and can be generated by endothelial cells. A tandem of electrochemical nanosensors (diameter 200-300 nm) were used to measure, in situ, the balance between NO and ONOO-produced by human umbilical vein endothelial cells (HUVEC’s). The amperometric nanosensors were placed 5 ± 2 μm from the surface of the endothelial cells and the concentration of NO and ONOO- was measured at 630 mV and -300 mV (vs Ag/AgCl) respectively. Normal, functional, endothelial cells produced maximal 450 ± 25 nmol.L-1 of NO and 180 ± 15 nmol.L-1 of ONOO- in about 3 s, after stimulation with calcium ionophore. The in situ measurements of NO and ONOO- were validated using nitric oxide synthase inhibitor L-NMMA, ONOO- scavenger Mn(III) porphyrin, and superoxide dismutase (PEG-SOD). The ratio of NO concentration to ONOO- concentration ([NO]/[ONOO-]) was introduced for quantification of both, the redox balance and the level of the nitroxidative stress in the endothelium. [NO]/[ONOO-] was 2.7 ± 0.1 in a functional endothelium. The model of the dysfunctional endothelium was made by the treatment of HUVEC’s with angiotensin II for 20 min. Dysfunctional HUVEC’s produced only 115 ± 15 nmol.L-1 of NO, but generated a significantly higher concentration of ONOO- of 490 ± 30 nmol.L-1. The [NO]/[ONOO-] ratio decreased to 0.23 ± 0.14 in the dysfunctional endothelium. Electrochemical nanosensors can be effectively used for in situ monitoring of changing levels of nitroxidative/ oxidative stress, and may be useful in early medical diagnosis of the cardiovascular system.
基金supported by the National Natural Science Foundation of China(U22A2075,U20A20209)the Fundamental Research Funds for the Central Universities(226-2022-00200)the Qianjiang Distinguished Experts program of Hangzhou.
文摘Ratiometric fluorescent detection of iron(Ⅲ)(Fe^(3+))offers inherent self-calibration and contactless analytic capabilities.However,realizing a dual-emission near-infrared(NIR)nanosensor with a low limit of detection(LOD)is rather challenging.In this work,we report the synthesis of water-dispersible erbium-hyperdoped silicon quantum dots(Si QDs:Er),which emit NIR light at the wavelengths of 810 and 1540 nm.A dual-emission NIR nanosensor based on water-dispersible Si QDs:Er enables ratiometric Fe^(3+)detection with a very low LOD(0.06μM).The effects of pH,recyclability,and the interplay between static and dynamic quenching mechanisms for Fe^(3+)detection have been systematically studied.In addition,we demonstrate that the nanosensor may be used to construct a sequential logic circuit with memory functions.
文摘A new fluorescence silver nanosensor assisted by surfactant has been recently synthesized and applied to ultra trace nickel determination. The methodology was validated by the standard addition method and satisfactorily applied to nickel determination in urine without previous treatment, coming from subjects with different smoking addiction levels and second hand smokers. Within-day precision was better than 0.011 CV. The reproducibility （between-days precision） was also evaluated over 3 days by performing six determinations each day with a CV of 0.025. The proposed methodology represents a promising approach in the area of biological monitoring due to its low operation cost, simplicity of instrumentation, high sampling speed and non-polluting solvents. Obtained results of urinary nickel concentration were successfully correlated with the tobacco addiction.
文摘A new fluorescence silver nanosensor assisted by surfactant has been synthesized and applied to ultra trace nickel determination. Operational variables which influence nanomaterial synthesis have been studied and optimized. Synthesis was very fast and simple using non polluting solvents; silver chemical reduction was carried out at room temperature. Spectroscopic studies were carried out in order to assure the uniformed of nanomaterial obtained. Fluorescent signal of silver nanoparticles resulted enhanced in presence of Ni（II）. At optimal experimental conditions, a detection limit of 0.036 pg＇L1 and quantification limit 0.12 pg＇L~ were obtained. The calibration sensitivity was 2 x 1014 L.pg-l.cm1 for the new methodology, with a range of linearity of six orders of magnitude between 0.12 and 2.93 × 10^5 pg L^-1. The tolerance levels for potential interferent ions were studied with good results. The proposed methodology represents a promising approach for Ni（II） traces quantification due to its low operation cost, simplicity of instrumentation, high sampling speed and non-polluting solvents.
基金Supported by grants from the National Natural Science Foundation of China(Nos.21171086 and 81160213)Inner Mongolia Grassland Talent(No.108-108038)+1 种基金Inner Mongolia Autonomous Region Natural Science Foundation(No.2013MS1121)the Inner Mongolia Agricultural University(Nos.211-109003 and 211-206038)
文摘Bio-nanosensors(Bio-NSs)have attracted much attention recently due to their unique properties.Among all of the bio-NSs,the intracellular proton sensor is significant for biomedicine studies and clinic diagnosis.Proton nanosensors(PNSs)with different pH sensitive ranges could satisfy different research requirements.Here we report a facile method to build a PNS with a neutral to basic pH sensitive range,in which the commercial pH indicator,fluoresceinamine(FA),was covalently coupled to the carboxylic-rich amphiphilic polymer(AP)coated gold nanoparticles(AuNPs).
基金supported by the National Natural Science Foundation of China(22274048,22274045,22376057,22274047,21904039,22474038,82273466)the Foundation of the Science&Technology Department of Hunan Province(2023JJ30394,2024JJ2039,2023ZJ1123)。
文摘Rapid and accurate diagnosis of oral cancer aggressiveness is associated with preoperative guidance and postoperative treatment.However,traditional diagnostic methods are time-consuming and easily misdiagnosed,which makes it challenging to achieve high-precision classification.Herein,we introduce a recognition engineering-mediated multichannel nanosensor for the analysis of tumor metabolites,allowing for sensitive and rapid in vitro and intraoperative cancer malignancy discrimination.This nanosensor system utilizes engineered carbon dots(CDs)with various ratios of amino and carboxyl functional groups,assembled as a“shell”on gold nanoparticles(AuNPs).The multichannel nanosensor displayed distinct fingerprint patterns for fourteen tumor metabolites such as amino acids,nucleic acids,and other metabolites.It offers rapid“turn-on”fluorescence-encoded profiling,generating unique signatures for cancer malignancy within 15 min.The nanosensor demonstrated 100%accuracy in identifying the oral squamous cell carcinoma(OSCC)subtype and assessing malignancy levels.It will provide detailed pathology for the identification of clinical cancer tissue samples,including cancer cell subtype and differentiation grade.Together,our study highlights the potential of the fluorescent-encoded multichannel nanosensor as a powerful in vitro and intraoperative diagnostic tool for cancer malignancy and treatment guidance in advanced clinical oncology.
文摘Stevia crystal can be defined as a botanical herb that has good properties to use as a substitute for sugar.The electrochemical study has been utilized for the purpose of calculating the limited dosage of the safety that should be used in black tea by cyclic voltammetry(CV)technique using the nanosensor as a more effective glassy carbon electrode(GCE)and carbon nanotubes(CNTs).Stevia’s oxidation current peak has been 400 mV at 0.40 mmol/L concentration(i.e.28 mg/mL),and reduction current peaks at 600 and–600 mV.It leads to the conclusion that stevia is a limited concentration antioxidant component safe for use in black tea.Additionally,electro-chemical characteristics of the stevia compound in the black tea have been investigated at alkaline and acidic pH in order to give oxidizing behaviors in the alkaline medium,while in an acidic medium as an antioxidant agent in black tea.Other chemical properties such as different scan rates,reliability,and stability have also been investigated.
基金Supported by the Key Project of National Natural Science Foundation of China (Grant No. 20135010)the National Key Basic Research Program of China (Grant No. 2002CB513100-10)+3 种基金the Key Technology Research and Development Program of China (Grant No. 2003BA310A16)the High-Tech Research and Development Program of China (Grant No. 2003AA302250)the International Cooperation Key Project of Science and Technology Ministry (Grant No. 2003DF000039)the National Natural Science Foundation of China (Grant No. 20405005)
文摘In this paper,the relationship of intracellular acidification and apoptosis in Hela cells induced by vin-cristine sulfate has been studied by use of the ratiometric pH nanosensors that have been developed by our group,employing fluorescein isothiocyanate(FITC) doped as the pH-sensitive dye and Tris(2,2'-bipyidyl) dichlororuthenium(II) hexahydrate(RuBpy) doped as reference dye. The pH change of the Hela cells induced by vincristine sulfate has been monitored in vivo,in situ and real time by use of the ratiometric pH nanosensors. The experimental results show that the pH of the apoptotic Hela cells induced by vincristine sulfate has been acidified from 7.11 to 6.51,and the percentage of intra-cellular acidification is correlated with the induced concentration and incubation time of the vincristine sulfate. The further study of the percentage of intracellular acidification and the percentage of apop-tosis of Hela cells at the same time reveals that apoptosis of Hela cells induced by vincristine sulfate is preceded by intracellular acidification. These results would provide theoretical foundation for the therapy of cancer through interfering the pH of cells by use of vincristine sulfate or other anti-cancer drugs.
文摘Applications based on silicene as grown on substrates are of high interest toward actual utilization of this unique material. Here we explore, from first principles, the nature of carbon monoxide adsorption on semiconducting silicene nanoribbons and the resulting quantum conduction modulation with and without silver contacts for sensing applications. We find that quantum conduction is detectably modified by weak chemisorption of a single CO molecule on a pristine silicene nanoribbon. This modification can be attributed to the charge transfer from CO to the silicene nanoribbon and the deformation induced by the CO chemisorption. Moderate binding energies provide an optimal mix of high detectability and recoverability. With Ag contacts attached to a -1 nm silicene nanoribbon, the interface states mask the conductance modulations caused by CO adsorption, emphasizing length effects for sensor applications. The effects of atmospheric gases--nitrogen, oxygen, carbon dioxide, and water--as well as CO adsorption density and edge-dangling bond defects, on sensor functionality are also investigated. Our results reveal pristine silicene nanoribbons as a promising new sensing material with single molecule resolution.
文摘Water pollution accidents, such as the Flint water crisis in the United States, caused by lead contamination have raised concern on the safety of drinking water distribution systems. Thus, the routine monitoring of lead in water is highly required and demands efficient, sensitive, cost-effective, and reliable lead detection methods. This study reports a label-free colorimetric nanosensor that uses unmodified gold nanoparticles (AuNPs) as indicators to enable rapid and ultra-sensitive detection of lead in environmental water. The 8-17 DNAzyme was truncated in this study to facilitate the detachment of single-stranded DNA fragments after substrate cleavage in the presence of Pb「. The detached fragments were adsorbed over AuNPs and protected against salt concentration-induced aggregation. Accordingly, high Pb^2+ would result in rapid color change from blue to pink. The established sensing principle achieved a sensitive limit of detection of 0.2×10^-9mol/L Pb^2+. with a linear working range of two orders of magnitude from 0.5×10^-9mol/L to 5×10^-9mol/L. The selectivity of the nanosensor was demonstrated by evaluating the interfering metal ions. The developed nanosensor can serve as a substitute for the rapid analysis and monitoring of trace lead levels under the drinking water distribution system and even other environmental water samples.
文摘Although nanotechnology has led to important advances in in vitro diagnostics, the development of nanosensors for in vivo detection remains very challenging. Here, we demonstrated the proof-of-principle of in vivo detection of nudeic acid targets using a promising type of surface-enhanced Raman scattering （SERS） nanosensor implanted in the skin of a large animal model （pig）. The in vivo nanosensor used in this study involves the ＂inverse molecular sentinel＂ detection scheme using plasmonics-active nanostars, which have tunable absorption bands in the near infrared region of the ＂tissue optical window＂, rendering them efficient as an optical sensing platform for in vivo optical detection. Ex vivo measurements were also performed using human skin grafts to demonstrate the detection of SERS nanosensors through tissue. In this stud, a new core--shell nanorattle probe with Raman reporters trapped between the core and shell was utilized as an internal standard system for self-calibration. These results illustrate the usefulness and translational potential of the SERS nanosensor for in vivo biosensing.
基金This work was supported by the Shenzhen Municipal Science and Technology Innovation Council(JCYJ20180504165819965)the National Natural Science Foundation of China(No.21874063)The authors acknowledge the technical support from SUSTech Core Research Facilities。
文摘Compared with conventional water-soluble fluorescence probes,pH-sensitive fluorescent nanosensors based on hydrophobic indicators remain largely unexplored.We report here the unique pH response of the nanosensors with a hydrophobic indicator(Ch3,a Nile Blue derivative)in polymeric nanoparticles(NPs).At the aqueous-organic interface of the NPs,spectral overlap and dye accumulation caused significant Förster resonance energy transfer(FRET)not only between the protonated and deprotonated Ch3(hetero-FRET),but also between the protonated and deprotonated Ch3 themselves(homo-FRET).The pH response was simulated according to an interfacial response mechanism and the dynamic range was found to depend on the size of the NPs and dye distribution(Kp).Therefore,adjusting the size of the NPs and the local dye concentration gave rise to a series of dynamic sensing ranges with apparent pKa values from 2.7 to 9.6 based on a single indicator.The nanosensors were successfully delivered to HeLa cells to monitor subcellular pH values in the endosomes and lysosomes.Based on cellular calibrations,the average pH in the organelles were determined to be ca.4.7.Moreover,the pH neutralization process during lysosome membrane permeabilization(LMP)induced by hydrogen peroxide stimulation was also successfully visualized with the nanosensors.
基金supported by the National Natural Science Foundation of China (51572009)
文摘A general stepwise strategy for the preparation of new humidity-responsive plasmonic nanosensor was described for the first time, based on Ag film functionalization by polyacrylamide（PAAM） brushes via surface-initiated atom transfer radical polymerization（SI-ATRP） method and then assembled with gold nanoparticles（Au NPs）. We designed by this way a new plasmonic device made of Au NPs embedded in a humid vapor responsive polymer layer on Ag film and extensively characterized by surface-enhanced Raman scattering（SERS）. When the relative humidity（RH） is above 50%, the number of plasmonic hotspots decreases, causing SERS signal reduced noticeably, for the volume expansion of PAAM brushes varied the nano-gap between closely spaced Au NPs, and between Au NPs and Ag film. The reversible optical properties of the prepared nanocomposite tuned by RH were probed through SERS using 4-mercaptopyridine（4-Mpy） as a molecular probe, and the decrease of the RH reversibly induces a significant enhancement of the 4-Mpy SERS signal. By means of the high reversibility, the RH responsive nanocomposite developed in this paper provides a dynamic SERS platform and can be applied as plasmonic nanosensor which is proved to be stable for at least two months.
基金supported by the National Natural Sci-ence Foundation of China(grant nos.21327902,21675080,and 21974059)the Natural Science Founda-tion of Jiangsu Province(grant no.BK20170073)the Excellent Research Program of Nanjing University(no.ZYJH004).
文摘Intracellular potassium ions(K^(+))play pivotal roles in many physiological processes.Several K^(+)sensors have been developed for probing cellular K^(+)fluctuations.Nevertheless,the existing solutions are incompatible and impractical for intracellular K^(+)probing.Herein,we report a supersmall biomimetic K^(+)nanosensor to serve as a transmembrane vector capable of electrochemically detecting intracellular K^(+)in a minimally invasive manner.
基金This work was supported by the Czech Science Foundation(GAČR,No.22-14886S)the MCIN/AEI/10.13039/501100011033(No.PID2019-107697RBC42(ERDF A way of making Europe)).
文摘This work focuses on the fabrication and characterization of Chemical Field-Effect Transistor(ChemFET)gas nanosensor arrays based on single nanowire(SNW).The fabrication processes include micro and nanofabrication techniques enabled by a combination of ultraviolet(UV)and e-beam lithography to build the ChemFET structure.Results show the integration and connection of SNWs across the multiple pairs of nanoelectrodes in the ChemFET by dielectrophoresis process(DEP)thanks to the incorporation of alignment windows(200-300 nm)adapted to the diameter of the NWs.Measurements of the SNW ChemFET array's output and transfer characteristics prove the influence of gate bias on the drain current regulation.Tests upon hydrogen(H_(2))and nitrogen dioxide(NO_(2))as analyte models of reducing and oxidizing gases show the ChemFET sensing functionality.Moreover,results demonstrate better response characteristics to H_(2)when the ChemFET operates in the subthreshold regime.The design concepts and methods proposed for fabricating the SNW-based ChemFET arrays are versatile,reproducible,and most likely adaptable to other systems where SNW arrays are required.
