Key Laboratory of Analysis and Detection for Food Safety (MOE & Fujian Province), Collaborative Innovation Center of Detection Technology for Haixi Food Safety and Products (Fujian Province), State Key Laboratory of Photocatalysis on Energy and Environment, Department of Chemistry, Fuzhou University, Fuzhou 350116, PR China.
Key Laboratory of Analysis and Detection for Food Safety (MOE & Fujian Province), Collaborative Innovation Center of Detection Technology for Haixi Food Safety and Products (Fujian Province), State Key Laboratory of Photocatalysis on Energy and Environment, Department of Chemistry, Fuzhou University, Fuzhou 350116, PR China.
Biosens Bioelectron. 2017 Oct 15;96:317-323. doi: 10.1016/j.bios.2017.05.027. Epub 2017 May 13.
A novel p-type semiconductor material (p-CuBiO) is designed for the construction of split-type photoelectrochemical (PEC) immunosensor for alpha-fetoprotein (AFP) with the hemin assistant to enhance the cathodic photocurrent. Initially, the photocathode of PEC immunosensor is fabricated by p-CuBiO on a layer of gold nanoparticles (AuNPs, as a front contact of p-CuBiO) to enhance the efficiency of charge separation. In the presence of target AFP, a sandwich-type immunoreaction was carried out in capture antibody-coated microplate by using detection antibody and hemin-based G-quadruplex (labeled on the AuNP) as the signal probe. Upon exonuclease I (Exo I) introduction, the enzyme digested the hemin/G-quadruplex-based DNAzyme to release the hemin[Fe(III)], which captured the generated electrons of p-CuBiO-based photocathode to enhance photocurrent via the reduction of hemin[Fe(III)] to hemin[Fe(II)] in PEC detection system. Under the optimal conditions, the split-type photocathodic immunosensor showed a wide linear dynamic range from 50pgmL to 20ngmL at a limit of detection (LOD) of 14.7pgmL toward target AFP. Moreover, the PEC immunosensor also displayed high specificity and good reproducibility. Favorably, method accuracy was evaluated to analyze human serum specimens, and gave matched-well results in comparison with commercially available enzyme-linked immunosorbent assay (ELISA) method.
一种新型的 p 型半导体材料（p-CuBiO）被设计用于构建用于检测甲胎蛋白（AFP）的分体式光电化学（PEC）免疫传感器，其中血红素辅助剂用于增强阴极光电流。首先，PEC 免疫传感器的光阴极通过 p-CuBiO 制备在一层金纳米粒子（AuNPs，作为 p-CuBiO 的前接触）上，以提高电荷分离效率。在存在目标 AFP 的情况下，夹心型免疫反应在捕获抗体涂覆的微孔板中进行，使用检测抗体和基于血红素的 G-四链体（标记在 AuNP 上）作为信号探针。引入外切酶 I（Exo I）后，酶消化血红素/G-四链体基 DNA 酶以释放血红素[Fe(III)]，该血红素[Fe(III)]捕获基于 p-CuBiO 的光阴极产生的电子，通过在 PEC 检测系统中还原血红素[Fe(III)]为血红素[Fe(II)]来增强光电流。在最佳条件下，分体式光阴极免疫传感器对目标 AFP 的检测范围从 50pgmL 到 20ngmL，检测限（LOD）为 14.7pgmL。此外，PEC 免疫传感器还表现出高特异性和良好的重现性。有利的是，该方法的准确性通过分析人血清标本进行了评估，并与市售的酶联免疫吸附测定（ELISA）方法进行了匹配。
