A sensitive electrochemical impedance immunosensor for determination of malachite green and leucomalachite green in the aqueous environment

作者：Zhu, Dan; Li, Qiangqiang; Pang, Xiumei; Liu, Yue; Wang, Xue; Chen, Gang^*

来源：Analytical and Bioanalytical Chemistry, 2016, 408(20): 5593-5600.

DOI：10.1007/s00216-016-9660-3

• Leucomalachite green
• Malachite green
• Antibody
• Electrochemical impedance spectroscopy
• Water environment

Application of malachite green (MG) and leucomalachite green (LMG) in fish farm water causes an environmental problem. This study proposes for the first time a sensitive and convenient electrochemical impedance spectroscopy (EIS) method for determining MG and LMG by a bovine serum albumin-decorated gold nanocluster (BSA-AuNC)/antibody composite film-based immunosensor. In order to improve the analytical performance, the glassy carbon electrode (GCE) was modified with 1, 4-phenylenediamine to form a stable layer, and then, BSA-AuNCs were covalently bound to the GCE. An adequate quantity of the polyclonal antibody of LMG was immobilized onto the surface of the BSA-AuNCs by the chemical reaction of EDC/NHS. The sensors can respond to the specific target based on specific covalent bonding. The experimental parameters, such as the pH, incubating concentration, and time, have been investigated and optimized. The calibration curve for LMG was linear in the range of 0.1 similar to 10.0 ng/mL with the limit of detection (LOD) 0.03 ng/mL. Furthermore, the sum of MG and LMG was detected in fish farm water by MG reduction. The recovery was between 89.7 % and 99.2 % in spiked samples. The EC sensor method was also compared with the ELISA method and validated by the LC-MS/MS method, which proves its great promise as a field instrument for the rapid monitoring of MG and LMG pollution.

• 出版日期2016-8
• 单位中国农业科学院; 浙江工业大学