A competitive-displacement reaction strategy based on target-induced dissociation of gold nanoparticle coated graphene nanosheet (AuNPs/GN) from CdS quantum dot functionalized mesoporous titanium dioxide (CdS QDs/TiO₂) was designed for the sensitive photoelectrochemical (PEC) aptasensing of prostate-specific antigen (PSA) through the exciton–plasmon interaction (EPI) between CdS QDs and AuNPs. To construct such an aptasensing system, capture DNA was initially conjugated covalently onto CdS QDs/TiO₂-modified electrode, and then AuNPs/GN-labeled PSA aptamer was bound onto biofunctionalized CdS QDs/TiO₂ via hybridization chain reaction of partial bases with capture DNA. Introduction of AuNPs/GN efficiently quenched the photocurrent of CdS QDs/TiO₂ thanks to energy transfer. Upon addition of target PSA, the sandwiched aptamer between CdS QDs/TiO₂ and AuNPs/GN reacted with the analyte analyte, thus resulting in the dissociation of AuNPs/GN from the CdS QDs/TiO₂ to increase the photocurrent. Under optimum conditions, the aptasensing platform exhibited a high sensitivity for PSA detection within a dynamic linear range of 1.0 pg/mL to 8.0 ng/mL at a low limitat of detection of 0.52 pg/mL. The interparticle distance of exciton–plasmon interaction and contents of AuNPs corresponding to EPI effect in this system were also studied. Good selectivity and high reproducibility were obtained for the analysis of target PSA. Importantly, the accuracy and matrix effect of PEC aptasensor was evaluated for the determination of human serum specimens and newborn calf serum-diluted PSA standards, giving a well-matched result with the referenced PSA ELISA kit.

中文翻译：

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AuNPs /石墨烯纳米杂化物与CdS量子点/ TiO ₂之间的激子-等离子体相互作用对前列腺特异性抗原的光电化学吸附

设计了一种基于目标诱导的金纳米颗粒包覆的石墨烯纳米片（AuNPs / GN）从CdS量子点功能化介孔二氧化钛（CdS QDs / TiO ₂）解离的竞争置换反应策略，用于前列腺的灵敏光电化学（PEC）适应性。 CdS QD和AuNP之间的激子-等离子体激元相互作用（EPI）产生特异性抗原（PSA）。为了构建这样的适体系统，首先将捕获的DNA共价结合到CdS QDs / TiO ₂修饰的电极上，然后通过部分碱基与捕获的杂交链反应将AuNPs / GN标记的PSA适体结合到生物功能化的CdS QDs / TiO ₂上。脱氧核糖核酸。AuNPs / GN的引入有效地消除了CdS QDs / TiO ₂的光电流多亏了能量转移。添加目标PSA后，夹在CdS QDs / TiO ₂和AuNPs / GN之间的适体与分析物分析物发生反应，从而导致AuNPs / GN从CdS QDs / TiO _2中解离。增加光电流。在最佳条件下，适体平台在1.0 pg / mL至8.0 ng / mL的动态线性范围内对PSA检测显示出高灵敏度，而检测限为0.52 pg / mL。还研究了该系统中激子-等离子体相互作用的粒子间距离和对应于EPI效应的AuNPs的含量。对目标PSA的分析具有良好的选择性和高重现性。重要的是，评估了PEC aptasensor的准确性和基质效应，可用于测定人血清标本和新生牛犊血清稀释的PSA标准品，与参考的PSA ELISA试剂盒可得到很好的匹配结果。