中文摘要：

提出了一种基于纳米金／硫堇修饰金电极的ABA安培免疫传感器。该传感器基于H2O2-HRP-硫堇催化波体系构建，其中硫堇为传感介质。当HRP存在时，通过加入H2O2，硫堇的还原电流大幅增加，并且电流的增加依赖于HRP活性。HRP活性又由ABA与HRP酶标抗体结合物调控，产生一个减小的催化波。用BSA封闭硫堇单分子层修饰后可能存在的活性位点以避免非特异性吸附。优化了测定条件，包括酶标抗体和硫堇的最佳比例、培育时间、缓冲液的pH值和H2O2浓度。此传感器的还原电流在ABA浓度0．5～1000ng／mL范围内呈线性下降，回归方程为Y=0．0209x ＋17．071，相关系数为0．9922，检测限为0．2ng／mL。

英文摘要：

An amperometric immunosensor based on gold the determination of phytohormone abscisic acid （ABA） nanoparticle/thionine modified gold electrode for was proposed. The sensor was constructed based on the catalytic wave system of H2O2 and HRP with thionine as the medium. In the presence of HRP, the reduction current of thionine was substantially increased by the addition of H2O2 due to the catalytic wave system, and the current increase was dependent upon the activity of HRP. The activity of HRP could be modulated by the binding event of ABA to ABA-antibody conjugated HRP, producing a decrease in the catalytic wave. Bovine serum albumin （BSA） was employed to block the possible remaining active sites of the thionine monolayer to avoid the non-specific adsorption. Assay conditions were optimized including the proportion of ABA-antibody conjugated HRP and thionine, the incubation time, the pH of working buffer and the concentration of the H2O2. The reduction current of the immunosensor decreases linearly in the range of ABA from 0. 5 ng/mL to 1 000 ng/mL, while the linear regression equation was y=0. 020 9x ＋ 17. 071. The correlation coefficient was 0. 992 2. The detection limit was 0. 2 ng/mL.