A general strategy for photoelectrochemical immunoassay using an enzyme label combined with a CdS quantum dot/TiO₂ nanoparticle composite electrode.
A general strategy for photoelectrochemical immunoassay using an enzyme label combined with a CdS quantum dot/TiO₂ nanoparticle composite electrode.
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DOI：
10.1021/ac503969e
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发表时间：
2014-11
影响因子：
7.4
通讯作者：
Weiwei Zhao;Ru Chen;Pang Dai;Xiang-Ling Li;Jingjuan Xu;Hongyuan Chen
中科院分区：
文献类型：
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作者：
Weiwei Zhao;Ru Chen;Pang Dai;Xiang-Ling Li;Jingjuan Xu;Hongyuan Chen
光电化学（PEC）免疫分析由于其良好的分析性能和未来蛋白质分析的诱人潜力而受到越来越多的关注。这封信代表了一种新颖且通用的策略，用于在中性条件下对重要的心脏标志物肌钙蛋白 T (cTnT) 进行优雅的 PEC 免疫测定。具体来说，我们首先开发了一种高效的CdS量子点（QDs）/TiO2纳米粒子（NPs）光电极，在此基础上将精致的β-半乳糖苷酶（β-Gal）催化系统与夹心免疫结合相结合，用于探测cTnT。在pH 7.4下，β-Gal可以催化对氨基苯基吡喃半乳糖苷（PAPG）转化为对氨基苯酚（PAP），而对氨基苯酚（PAP）很容易被光氧化为对醌亚胺（PQI）。由于产生的光电流与目标浓度直接相关，因此可以实现用于 cTnT 检测的创新 PEC 免疫测定。该协议的中性操作条件将极大地有助于其在蛋白质测定中的广泛适用性。这项工作提供了第一个针对心脏标志物的 PEC 免疫测定，更重要的是，通过通用传感协议为未来 PEC 免疫测定的开发开辟了不同的视角。
Photoelectrochemical (PEC) immunoassay has received increasing attention owing to its good analytical performance and attractive potential for future protein assay. This Letter represents a novel and general strategy for elegant PEC immunoassay of the important cardiac marker troponin T (cTnT) at neutral conditions. Specifically, we first developed an efficient CdS quantum dots (QDs)/TiO2 nanoparticles (NPs) photoelectrode, on the basis of which an exquisite β-galactosidase (β-Gal) catalytic system was integrated with sandwich immunobinding for probing cTnT. In pH 7.4, β-Gal could catalyze the conversion of p-aminophenyl galactopyranoside (PAPG) to p-aminophenol (PAP), which could be easily photo-oxidized to p-quinone imine (PQI). Because the resulting photocurrent was directly related with the target concentration, an innovative PEC immunoassay could be realized for cTnT detection. The neutral operating condition of this protocol would greatly contribute to its wide applicability for protein assay. This work provides the first PEC immunoassay toward cardiac marker and, more significantly, opens a different perspective for future PEC immunoassay development through a general sensing protocol.