The kinetics of stripping of gold loaded in dibutyl carbito （DBC） organic phase by sodittm sulfite was investigated in a Lewis cell. After the stirring speed reached 400 r·min^-1, the reaction of gold stripping...The kinetics of stripping of gold loaded in dibutyl carbito （DBC） organic phase by sodittm sulfite was investigated in a Lewis cell. After the stirring speed reached 400 r·min^-1, the reaction of gold stripping conformed with the pseudo-first-order reaction. The stripping rate of gold was in direct proportion to interracial area, concentration of sodittm sulfite and reaction temperature. The experimental results showed that the process of stripping gold was controlled by interfacial chemical reaction, and its activation energy was 36.06 kJ·mol^-1. The kinetics equation was put forward for gold stripping by sodium sulfite.展开更多
A test strip was developed to rapidly detect fluoroquinolones in foods by colloidal gold immunochromatography method in combination with a food safety analyzer. The results showed that the test strip has the detection...A test strip was developed to rapidly detect fluoroquinolones in foods by colloidal gold immunochromatography method in combination with a food safety analyzer. The results showed that the test strip has the detection sensitivity of 20 μg/L for enrofloxacin, sarafloxacin, difloxacin, ofloxacin, norfloxacin, ciprofloxacin, pefloxacin, flumequine and danofloxacin, and the detection sensitivity of 40 μg/L for enoxacin and oxolinic acid. The test strip consumes only 10 min for detection, and the false positive rate and the false negative rate are both zero. The test strip can accurately, reliably and easily detect residual fluoroquinolones in foods, and is suitable for on-site detection of a large number of samples.展开更多
[Objectives] This study was conducted to establish a rapid detection method for spectinomycin in pork,chicken,fish,shrimp flesh and water.[Methods]A test strip for rapid detection of spectinomycin in milk was develope...[Objectives] This study was conducted to establish a rapid detection method for spectinomycin in pork,chicken,fish,shrimp flesh and water.[Methods]A test strip for rapid detection of spectinomycin in milk was developed by colloidal gold immunochromatography assay. [Results]The test strip had a detection limit of 50 μg/kg to milk with a detection time of 15 min,and the false positive rate and false negative rate were both 0. [Conclusions]The method is accurate,simple,reliable and convenient,and is suitable for rapid on-site spectinomycin detection.展开更多
A novel sensitive electrochemical immunoassay with colloidal gold as the antibody labeling tag and subsequent signal amplification by silver enhancement is described. Colloidal gold was treated by a light-sensitive si...A novel sensitive electrochemical immunoassay with colloidal gold as the antibody labeling tag and subsequent signal amplification by silver enhancement is described. Colloidal gold was treated by a light-sensitive silver enhancement system which made silver deposit on the surface of colloidal gold(form Au/Ag core-shell structure), followed by the release of the metallic silver atoms anchored on the antibody by oxidative dissolution of them in an acidic solution and the indirect determination of the dissolved Ag + ions by anodic stripping voltammetry(ASV) at a carbon fiber microelectrode. The electrochemical signal is directly proportional to the amount of analyte(goat IgG) in the standard or a sample. The method was evaluated by means of a noncompetitive heterogeneous immunoassay of immunoglobulin G(IgG) with a concentration as low as 0.2 ng/mL. The high performance of the method is related to the sensitive ASV determination of silver(Ⅰ) at a carbon fiber microelectrode and to the release of a large number of Ag + ions from each silver shell anchored on the analyte(goat IgG).展开更多
The nano-gold layer formed on the platinum rotating disk electrode (nano-Au/Pt-RD) inherited the catalytic property for Cr(VI) reduction from platinum surface and owned the good features of nano-gold such as insensiti...The nano-gold layer formed on the platinum rotating disk electrode (nano-Au/Pt-RD) inherited the catalytic property for Cr(VI) reduction from platinum surface and owned the good features of nano-gold such as insensitivity with hydrogen ion, high surface area, augmenting diffusion of Cr(VI) and ability for self-assembling with 4-pyridine-ethanethiol (PET) through Au←S linkages, to form PET/nano-Au/Pt-RD electrode capable of accumulating Cr(VI) from sample. The obtained PET/ nano-Au/Pt-RD electrode showed an extreme sensitivity to Cr(VI). By using this electrode, 1.09 ng·L﹣1 was the detection limit of differential pulse adsorptive cathodic stripping voltammetry for Cr(VI) with the accumulation time of only 2 min. Moreover, this electrode was reproducible with 3.5% RSD for 30 times of Cr(VI) accumulating and stripping. In addition, this electrode was also selective for Cr(VI) determination, which was not almost interfered by other inorganic ions.展开更多
文摘The kinetics of stripping of gold loaded in dibutyl carbito （DBC） organic phase by sodittm sulfite was investigated in a Lewis cell. After the stirring speed reached 400 r·min^-1, the reaction of gold stripping conformed with the pseudo-first-order reaction. The stripping rate of gold was in direct proportion to interracial area, concentration of sodittm sulfite and reaction temperature. The experimental results showed that the process of stripping gold was controlled by interfacial chemical reaction, and its activation energy was 36.06 kJ·mol^-1. The kinetics equation was put forward for gold stripping by sodium sulfite.
基金Supported by Beijing Training Project for the Leading Talents in S&T(Z171100001117158)
文摘A test strip was developed to rapidly detect fluoroquinolones in foods by colloidal gold immunochromatography method in combination with a food safety analyzer. The results showed that the test strip has the detection sensitivity of 20 μg/L for enrofloxacin, sarafloxacin, difloxacin, ofloxacin, norfloxacin, ciprofloxacin, pefloxacin, flumequine and danofloxacin, and the detection sensitivity of 40 μg/L for enoxacin and oxolinic acid. The test strip consumes only 10 min for detection, and the false positive rate and the false negative rate are both zero. The test strip can accurately, reliably and easily detect residual fluoroquinolones in foods, and is suitable for on-site detection of a large number of samples.
基金Supported by Beijing Training Project for the Leading Talents in Science and Technology(Z171100001117158)
文摘[Objectives] This study was conducted to establish a rapid detection method for spectinomycin in pork,chicken,fish,shrimp flesh and water.[Methods]A test strip for rapid detection of spectinomycin in milk was developed by colloidal gold immunochromatography assay. [Results]The test strip had a detection limit of 50 μg/kg to milk with a detection time of 15 min,and the false positive rate and false negative rate were both 0. [Conclusions]The method is accurate,simple,reliable and convenient,and is suitable for rapid on-site spectinomycin detection.
基金Supportted by the National Natural Science Foundation of China( No.2 0 0 730 16 ,6 0 2 710 2 0 ),86 3projects( No.2 0 0 2 AA302203)and973projects( No.G19990 6 4 5 0 4 )
文摘A novel sensitive electrochemical immunoassay with colloidal gold as the antibody labeling tag and subsequent signal amplification by silver enhancement is described. Colloidal gold was treated by a light-sensitive silver enhancement system which made silver deposit on the surface of colloidal gold(form Au/Ag core-shell structure), followed by the release of the metallic silver atoms anchored on the antibody by oxidative dissolution of them in an acidic solution and the indirect determination of the dissolved Ag + ions by anodic stripping voltammetry(ASV) at a carbon fiber microelectrode. The electrochemical signal is directly proportional to the amount of analyte(goat IgG) in the standard or a sample. The method was evaluated by means of a noncompetitive heterogeneous immunoassay of immunoglobulin G(IgG) with a concentration as low as 0.2 ng/mL. The high performance of the method is related to the sensitive ASV determination of silver(Ⅰ) at a carbon fiber microelectrode and to the release of a large number of Ag + ions from each silver shell anchored on the analyte(goat IgG).
文摘The nano-gold layer formed on the platinum rotating disk electrode (nano-Au/Pt-RD) inherited the catalytic property for Cr(VI) reduction from platinum surface and owned the good features of nano-gold such as insensitivity with hydrogen ion, high surface area, augmenting diffusion of Cr(VI) and ability for self-assembling with 4-pyridine-ethanethiol (PET) through Au←S linkages, to form PET/nano-Au/Pt-RD electrode capable of accumulating Cr(VI) from sample. The obtained PET/ nano-Au/Pt-RD electrode showed an extreme sensitivity to Cr(VI). By using this electrode, 1.09 ng·L﹣1 was the detection limit of differential pulse adsorptive cathodic stripping voltammetry for Cr(VI) with the accumulation time of only 2 min. Moreover, this electrode was reproducible with 3.5% RSD for 30 times of Cr(VI) accumulating and stripping. In addition, this electrode was also selective for Cr(VI) determination, which was not almost interfered by other inorganic ions.
