The applicability of a gold nanoparticle-modified glassy carbon sensor （AuNPs-GCS） for the determination of inorganic mercury in fresh and canned tuna fish by square wave anodic stripping voltammetry （SW-ASV） is d...The applicability of a gold nanoparticle-modified glassy carbon sensor （AuNPs-GCS） for the determination of inorganic mercury in fresh and canned tuna fish by square wave anodic stripping voltammetry （SW-ASV） is demonstrated. Mercury content in sample Tuna Fish ISPRA T22 was determined to value the accuracy of the determination. The concentration in this sample is not certified, so, the Hg amount was determined also with atomic absorption spectroscopy （AAS）： the results obtained with ASV were in good agreement and confirmed literature value reported for this sample. Then, real samples of tuna fish were analyzed. The voltammetric analyses were performed using previously optimized conditions （deposition potential 0 V, step potential 0.004 V, frequency 150 Hz and amplitude 0.003 V）. Medium exchange technique permitted to eliminate possible matrix effects. The concentrations in the real samples were found to be in agreement with the common Hg levels reported in literature for commercialized tuna fish in different countries.展开更多
Transcription factor and sequence specific DNA interactions play important roles in drug genome and transcription diagnosis. Gold nanoparticles show high sensitivity, stability and compatibility for biological molecul...Transcription factor and sequence specific DNA interactions play important roles in drug genome and transcription diagnosis. Gold nanoparticles show high sensitivity, stability and compatibility for biological molecules as electrochemical intercalators. Here unimolecular hairpin oligonucleotides were self-assembled onto Au electrode surface and elongation on solid phase was carried out to double strand oligonucleotides with transcription factor NF-r,13 binding site. Gold nanoparticle-catalyzed Ag deposition was detected by anodic stripping voltammetry （ASV） for NF-kB binding. It was indicated that this method for sequence specific DNA binding protein detection shows pronounced specificity, sensitivity and we can find application in transcription regulation research, open reading frame characterization and functional gene inspection by this method.展开更多
The present work is concerned with the voltammetric application of unmodified tricresyl phosphate carbon paste electrode （TCP-CPE） and in situ bismuth-film modified tricresyl phosphate-based carbon paste electrode ...The present work is concerned with the voltammetric application of unmodified tricresyl phosphate carbon paste electrode （TCP-CPE） and in situ bismuth-film modified tricresyl phosphate-based carbon paste electrode （BiF-TCP-CPE）. The TCP-CPE was examined with the main objective of using it for the differential pulse voltammetric analysis of some neonicotinoid insecticides in aqueous Britton-Robinson buffer solution pH 7.0 as supporting electrolyte. After comparing the performance of the TCP-CPE with that of silicone oil carbon paste electrode, quantitative analysis of imidacloprid, thiamethoxam and clothianidin was performed in model solutions and real samples （river water and commercial insecticide formulations）. The in situ prepared BiF-TCP-CPE was tested for a simultaneous detection of selected heavy metal ions （Cd^2＋ and Pb^2＋） at a μg/dm^3 concentration level, using square wave anodic stripping voltammetric technique. The influence of different electrochemical pretreatments of the working electrode on the bismuth deposition and analyte signals were investigated. Film formation was studied at untreated, pre-cathodized and pre-anodized TCP-CPEs in the acetic buffer solution pH 4.6, containing 1 μg/cm^3 Bi （III）.展开更多
Sensitive and selective detection of Hg（II） contamination is of great importance with concern of public health. Herein, we successfully fabricated monolayer MoS2 （S-MoS2） decorated Cu7S4-Au （Cu7S4-Au@S-MoS2） nan...Sensitive and selective detection of Hg（II） contamination is of great importance with concern of public health. Herein, we successfully fabricated monolayer MoS2 （S-MoS2） decorated Cu7S4-Au （Cu7S4-Au@S-MoS2） nanocomposite modified electrode for the sensitive and selective detection of Hg（II） via anodic stripping voltammetric technique. Due to the excellent electrocatalytic reduction performance arisen from the abundant active edge sites of small monolayer MoS2 and good affinity of Au toward Hg, the current method displayed high sensitivity （LOD = 190 nmol L-l） and enhanced selectivity. As control, nanostructures including Cu7S4-Au, Cu7S4@S-MoS2 and Cu7S4-Au@M-MoS2 （M： multilayer） were also investigated, but showed low re- sponse to Hg（Ⅱ）, suggesting that both Au domains and active edge sites of monolayer MoS2 have crucial synergistic effects on the high-performance for recognition of Hg（Ⅱ）. Moreover, the developed method displays satisfied performance for the detection of Hg（Ⅱ） in real samples, which indicates its potentials in practical applications.展开更多
文摘The applicability of a gold nanoparticle-modified glassy carbon sensor （AuNPs-GCS） for the determination of inorganic mercury in fresh and canned tuna fish by square wave anodic stripping voltammetry （SW-ASV） is demonstrated. Mercury content in sample Tuna Fish ISPRA T22 was determined to value the accuracy of the determination. The concentration in this sample is not certified, so, the Hg amount was determined also with atomic absorption spectroscopy （AAS）： the results obtained with ASV were in good agreement and confirmed literature value reported for this sample. Then, real samples of tuna fish were analyzed. The voltammetric analyses were performed using previously optimized conditions （deposition potential 0 V, step potential 0.004 V, frequency 150 Hz and amplitude 0.003 V）. Medium exchange technique permitted to eliminate possible matrix effects. The concentrations in the real samples were found to be in agreement with the common Hg levels reported in literature for commercialized tuna fish in different countries.
基金This research is financially supported by the National Natural Science Foundation （No. 90606027 60501010）.
文摘Transcription factor and sequence specific DNA interactions play important roles in drug genome and transcription diagnosis. Gold nanoparticles show high sensitivity, stability and compatibility for biological molecules as electrochemical intercalators. Here unimolecular hairpin oligonucleotides were self-assembled onto Au electrode surface and elongation on solid phase was carried out to double strand oligonucleotides with transcription factor NF-r,13 binding site. Gold nanoparticle-catalyzed Ag deposition was detected by anodic stripping voltammetry （ASV） for NF-kB binding. It was indicated that this method for sequence specific DNA binding protein detection shows pronounced specificity, sensitivity and we can find application in transcription regulation research, open reading frame characterization and functional gene inspection by this method.
文摘The present work is concerned with the voltammetric application of unmodified tricresyl phosphate carbon paste electrode （TCP-CPE） and in situ bismuth-film modified tricresyl phosphate-based carbon paste electrode （BiF-TCP-CPE）. The TCP-CPE was examined with the main objective of using it for the differential pulse voltammetric analysis of some neonicotinoid insecticides in aqueous Britton-Robinson buffer solution pH 7.0 as supporting electrolyte. After comparing the performance of the TCP-CPE with that of silicone oil carbon paste electrode, quantitative analysis of imidacloprid, thiamethoxam and clothianidin was performed in model solutions and real samples （river water and commercial insecticide formulations）. The in situ prepared BiF-TCP-CPE was tested for a simultaneous detection of selected heavy metal ions （Cd^2＋ and Pb^2＋） at a μg/dm^3 concentration level, using square wave anodic stripping voltammetric technique. The influence of different electrochemical pretreatments of the working electrode on the bismuth deposition and analyte signals were investigated. Film formation was studied at untreated, pre-cathodized and pre-anodized TCP-CPEs in the acetic buffer solution pH 4.6, containing 1 μg/cm^3 Bi （III）.
基金supported by the National Natural Science Foundation of China(21475007 and 21675009)the Fundamental Research Funds for Central Universities(buctrc201507 and buctrc201608)the support from the "Public Hatching Platform for Recruited Talents of BUCT"
文摘Sensitive and selective detection of Hg（II） contamination is of great importance with concern of public health. Herein, we successfully fabricated monolayer MoS2 （S-MoS2） decorated Cu7S4-Au （Cu7S4-Au@S-MoS2） nanocomposite modified electrode for the sensitive and selective detection of Hg（II） via anodic stripping voltammetric technique. Due to the excellent electrocatalytic reduction performance arisen from the abundant active edge sites of small monolayer MoS2 and good affinity of Au toward Hg, the current method displayed high sensitivity （LOD = 190 nmol L-l） and enhanced selectivity. As control, nanostructures including Cu7S4-Au, Cu7S4@S-MoS2 and Cu7S4-Au@M-MoS2 （M： multilayer） were also investigated, but showed low re- sponse to Hg（Ⅱ）, suggesting that both Au domains and active edge sites of monolayer MoS2 have crucial synergistic effects on the high-performance for recognition of Hg（Ⅱ）. Moreover, the developed method displays satisfied performance for the detection of Hg（Ⅱ） in real samples, which indicates its potentials in practical applications.
