Potentiometric competitive immunoassay for determination of aflatoxin B1 in food by using antibody-labeled gold nanoparticles
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- 作者：Qunfang Li ; Shuzhen Lv ; Minghua Lu ; Zhenzhen Lin ; Dianping Tang
- 关键词：Electroanalysis ; Biosensor ; Bioconjugation ; Immunosensor ; Peanut analysis ; Transmission electron microscopy ; Batch ; to ; batch identification
- 刊名：Microchimica Acta
- 出版年：2016
- 出版时间：October 2016
- 年：2016
- 卷：183
- 期：10
- 页码：2815-2822
- 全文大小：1,064 KB
- 刊物类别：Chemistry and Materials Science
- 刊物主题：Chemistry
Analytical Chemistry
Inorganic Chemistry
Physical Chemistry
Characterization and Evaluation Materials
Monitoring, Environmental Analysis and Environmental Ecotoxicology - 出版者：Springer Wien
- ISSN：1436-5073
- 卷排序：183
文摘
The authors report on a competitive potentiometric immunoassay for aflatoxin B1 (AFB1) in food that displays distinctly improved sensitivity. Gold nanoparticles (AuNPs; 16 nm i. d.) were functionalized with polyclonal anti-AFB1 antibody (pAb), whilst the sensor electrode was prepared by immobilizing AFB1-bovine serum albumin conjugate (AFB1-BSA) on a glassy carbon electrode. Upon addition of target AFB1, competitive immunobinding occurs between the analyte and AFB1-BSA for the labeled pAb on the AuNPs. The change in the surface charge as a result of the antigen-antibody reaction causes a shift in the electrical potential. With increasing concentrations of analyte (AFB1), the quantity of pAb-AuNP captured by the electrode decreases. The shift in the output potential is linearly proportional to the logarithm of AFB1 concentration in the 0.1 to 5.0 μg · kg−1 range, with a detection limit (LOD) of 87 ng · kg−1 (87 ppt). An intermediate precision of 10.9 % was accomplished in batch-to-batch identification. The selectivity over AFB2 with similar chemical structure is acceptable. The method accuracy was evaluated by analyzing naturally contaminated and spiked peanut samples, giving consistent results (with RSD values of <12 %) between this immunoassay and the commercial ELISA.