The development of efficient methods for the detection of hazardous and toxic elements is extremely important for environmental security and public health. In this work, we developed a facile colorimetric assaying sys...The development of efficient methods for the detection of hazardous and toxic elements is extremely important for environmental security and public health. In this work, we developed a facile colorimetric assaying system for Ag+ detection in aqueous solution. Chitosan-stabilized platinum nanoparticles(ChPtNPs) were synthesized and severed as an artificial oxidase to catalyze the oxidation of the substrate3,30,5,50-tetramethylbenzidine(TMB) and generate color signal. In the presence of Ag+, due to the strong metallophilic interactions between Ag+ and Pt2+ on the surface of Ch-PtNPs, Ag+ can weaken the affinity to the substrates and inactivate the catalytic activity of Ch-PtNPs, leading to decreased absorbance signal to varying degrees depending on Ag+ amount. Combing the specific binding between Ch-PtNPs and Ag+ with signal amplification procedure based on the Ch-PtNPs-catalyzed TMB oxidation, a sensitive,selective, simple, cost-effective, and rapid detection method for Ag+ can be realized. Ag+ ions in tap and lake waters have been successfully detected. We ensured that the proposed method can be a potential alternative for Ag+ determination in environmental samples.展开更多
Inspired by ballpoint pen,an optical biosensor is developed for detection of Salmonella using a mechanical step rotator with a dropper to greatly simplify operation,a high gradient magnetic field with immune magnetic ...Inspired by ballpoint pen,an optical biosensor is developed for detection of Salmonella using a mechanical step rotator with a dropper to greatly simplify operation,a high gradient magnetic field with immune magnetic nanobeads to specifically separate bacteria,and immune gold@platinum nanozymes with a smartphone to sensitively detect bacteria.First,the preloaded bacterial sample is drawn by the dropper to react with the immune magnetic nanobeads through repeated squeezing and releasing of the dropper,and the rotator is successively rotated and the dropper is repeatedly squeezed and released to achieve mixing of the bacteria,magnetic nanobeads and gold@platinum nanozymes,followed by magnetic separation to remove the background.Then,the conjugates are effectively washed with skim milk and ultrapure water,and the substrate are rapidly catalyzed into the product.Finally,the blue product is photographed and analyzed using a smartphone to obtain the Salmonella concentration.This biosensor could detect Salmonella as low as 56 CFU/mL in~25 min.展开更多
A microelectrode glucose biosensor based on a three-dimensional hybrid nanoporous platinum/graphene oxide nanostructure was developed for rapid glucose detection of tomato and cucumber fruits.The nanostructure was fab...A microelectrode glucose biosensor based on a three-dimensional hybrid nanoporous platinum/graphene oxide nanostructure was developed for rapid glucose detection of tomato and cucumber fruits.The nanostructure was fabricated by a two-step modification method on a microelectrode for loading a larger amount of glucose oxidase.The nanoporous structure was prepared on the surface of the platinum microelectrode by electrochemical etching,and then graphene oxide was deposited on the prepared nanoporous electrode by electrochemical deposition.The nanoporous platinum/graphene oxide nanostructure had the advantage of improving the effective surface area of the electrode and the loading quantity of glucose oxidase.As a result,the biosensor achieved a wide range of 0.1-20.0 mmol/L in glucose detection,which had the ability to accurately detect the glucose content.It was found that the three-dimensional hybrid nanostructure on the electrode surface realized the rapid direct electrochemistry of glucose oxidase.Therefore,the biosensor achieved high glucose detection sensitivity 11.64μA·L/(mmol.cm^(2)),low detection limit(13μmol/L)and rapid response time(reaching 95%steady-state response within 3 s),when calibrating in glucose standard solution.In agricultural application,the as-prepared biosensor was employed to detect the glucose concentration of tomato and cucumber samples.The results showed that the relative deviation of this method was less than 5%when compared with that of high-performance liquid chromatography,implying high accuracy of the presented biosensor in glucose detection in plants.展开更多
基金the financial support from the National Natural Science Foundation of China (Nos. 21075023, 21804021)the Program for Innovative Leading Talents in Fujian Province (No. 2016B016)+2 种基金the Joint Funds for the Innovation of Science and Technology, Fujian Province (No. 2016Y9056)the Natural Science Foundation of Fujian Province (No. 2017J01575)Startup Fund for Scientific Research, Fujian Medical University (No. 2017XQ1014)
文摘The development of efficient methods for the detection of hazardous and toxic elements is extremely important for environmental security and public health. In this work, we developed a facile colorimetric assaying system for Ag+ detection in aqueous solution. Chitosan-stabilized platinum nanoparticles(ChPtNPs) were synthesized and severed as an artificial oxidase to catalyze the oxidation of the substrate3,30,5,50-tetramethylbenzidine(TMB) and generate color signal. In the presence of Ag+, due to the strong metallophilic interactions between Ag+ and Pt2+ on the surface of Ch-PtNPs, Ag+ can weaken the affinity to the substrates and inactivate the catalytic activity of Ch-PtNPs, leading to decreased absorbance signal to varying degrees depending on Ag+ amount. Combing the specific binding between Ch-PtNPs and Ag+ with signal amplification procedure based on the Ch-PtNPs-catalyzed TMB oxidation, a sensitive,selective, simple, cost-effective, and rapid detection method for Ag+ can be realized. Ag+ ions in tap and lake waters have been successfully detected. We ensured that the proposed method can be a potential alternative for Ag+ determination in environmental samples.
基金supported by Pinduoduo-China Agricultural University Research Fund(PC2023B02021).
文摘Inspired by ballpoint pen,an optical biosensor is developed for detection of Salmonella using a mechanical step rotator with a dropper to greatly simplify operation,a high gradient magnetic field with immune magnetic nanobeads to specifically separate bacteria,and immune gold@platinum nanozymes with a smartphone to sensitively detect bacteria.First,the preloaded bacterial sample is drawn by the dropper to react with the immune magnetic nanobeads through repeated squeezing and releasing of the dropper,and the rotator is successively rotated and the dropper is repeatedly squeezed and released to achieve mixing of the bacteria,magnetic nanobeads and gold@platinum nanozymes,followed by magnetic separation to remove the background.Then,the conjugates are effectively washed with skim milk and ultrapure water,and the substrate are rapidly catalyzed into the product.Finally,the blue product is photographed and analyzed using a smartphone to obtain the Salmonella concentration.This biosensor could detect Salmonella as low as 56 CFU/mL in~25 min.
基金funded by the Key-Area Research and Development Program of Guangdong Province (2019B020219002)the Characteristic Innovation Project of Ordinary University of Guangdong Province (2019KTSCX018)+1 种基金the Guangdong Natural Science Funds for Distinguished Young Scholar (2014A030306005)the Guangdong Basic and Applied Basic Research Foundation (2019A1515110929),China.
文摘A microelectrode glucose biosensor based on a three-dimensional hybrid nanoporous platinum/graphene oxide nanostructure was developed for rapid glucose detection of tomato and cucumber fruits.The nanostructure was fabricated by a two-step modification method on a microelectrode for loading a larger amount of glucose oxidase.The nanoporous structure was prepared on the surface of the platinum microelectrode by electrochemical etching,and then graphene oxide was deposited on the prepared nanoporous electrode by electrochemical deposition.The nanoporous platinum/graphene oxide nanostructure had the advantage of improving the effective surface area of the electrode and the loading quantity of glucose oxidase.As a result,the biosensor achieved a wide range of 0.1-20.0 mmol/L in glucose detection,which had the ability to accurately detect the glucose content.It was found that the three-dimensional hybrid nanostructure on the electrode surface realized the rapid direct electrochemistry of glucose oxidase.Therefore,the biosensor achieved high glucose detection sensitivity 11.64μA·L/(mmol.cm^(2)),low detection limit(13μmol/L)and rapid response time(reaching 95%steady-state response within 3 s),when calibrating in glucose standard solution.In agricultural application,the as-prepared biosensor was employed to detect the glucose concentration of tomato and cucumber samples.The results showed that the relative deviation of this method was less than 5%when compared with that of high-performance liquid chromatography,implying high accuracy of the presented biosensor in glucose detection in plants.
