State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, P.R. China.
University of Science and Technology of China, Hefei, Anhui, 230026, P.R. China.
Analyst. 2022 May 3;147(9):1808-1814. doi: 10.1039/d1an02310a.
Enzyme-based sensing platforms have undergone rapid development in the field of diagnosis and bioanalysis. Here we present a novel fluorescent artificial enzyme-based detection strategy for L-cysteine (Cys) and HO by fabricating a series of Au-Ag bimetallic nanoparticles with peroxidase-like activity. Taking advantage of the enhanced performance of catalysts by optimizing the surface structure, the sensitive detection of Cys with an ultralow detection limit of 0.035 μM and accurate quantification in the range of 0.075-2 μM were achieved. It was revealed that the mechanism of the catalytic process on the Au-Ag surface follows the electron transfer mechanism rather than active species, that is the peroxidase-like catalysts work as electron transfer intermediates and the electron transfer efficiency will increase with the larger electron cloud density of active sites derived from the electronic synergistic effect between Au and Ag, contributing to the enhanced catalytic activity of peroxidase mimics. This finding could provide guidance for the structural design of high-activity peroxidase mimics.
基于酶的传感平台在诊断和生物分析领域得到了快速发展。在这里，我们通过构建一系列具有类过氧化物酶活性的 Au-Ag 双金属纳米粒子，提出了一种新颖的荧光人工酶检测 L-半胱氨酸（Cys）和 HO 的策略。利用通过优化表面结构来增强催化剂的性能，实现了对 Cys 的超灵敏检测，检测限低至 0.035 μM，在 0.075-2 μM 的范围内实现了准确的定量。研究表明，Au-Ag 表面上的催化过程机制遵循电子转移机制而不是活性物质，即类过氧化物酶催化剂作为电子转移中间体，电子转移效率会随着活性位点的电子云密度的增加而增加，这是由于 Au 和 Ag 之间的电子协同效应，从而提高了过氧化物酶模拟物的催化活性。这一发现为设计具有高活性的过氧化物酶模拟物提供了指导。
