Key Laboratory for Analytical Science of Food Safety and Biology (MOE & Fujian Province), State Key Laboratory of Photocatalysis on Energy and Environment, Department of Chemistry , Fuzhou University , Fuzhou 35011168 , People's Republic of China.
ACS Sens. 2018 Mar 23;3(3):632-639. doi: 10.1021/acssensors.7b00899. Epub 2018 Feb 23.
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/TiO) 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/TiO-modified electrode, and then AuNPs/GN-labeled PSA aptamer was bound onto biofunctionalized CdS QDs/TiO via hybridization chain reaction of partial bases with capture DNA. Introduction of AuNPs/GN efficiently quenched the photocurrent of CdS QDs/TiO thanks to energy transfer. Upon addition of target PSA, the sandwiched aptamer between CdS QDs/TiO and AuNPs/GN reacted with the analyte analyte, thus resulting in the dissociation of AuNPs/GN from the CdS QDs/TiO 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.
基于金纳米粒子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）上的目标诱导解离的竞争置换反应策略，通过 CdS QDs 和 AuNPs 之间的激子-等离子体相互作用（EPI），设计用于前列腺特异性抗原（PSA）的灵敏光电化学（PEC）适体传感。为了构建这种适体传感系统，首先将捕获 DNA 共价接枝到 CdS QDs/TiO 修饰的电极上，然后将 AuNPs/GN 标记的 PSA 适体通过与捕获 DNA 的部分碱基杂交链反应结合到生物功能化的 CdS QDs/TiO 上。由于能量转移，AuNPs/GN 的引入有效地猝灭了 CdS QDs/TiO 的光电流。加入靶标 PSA 后，CdS QDs/TiO 和 AuNPs/GN 之间夹在中间的适体与分析物发生反应，从而导致 AuNPs/GN 从 CdS QDs/TiO 上解离，增加光电流。在最佳条件下，该适体传感平台在 1.0 pg/mL 至 8.0 ng/mL 的动态线性范围内对 PSA 检测表现出高灵敏度，检测限低至 0.52 pg/mL。还研究了激子-等离子体相互作用的粒子间距离和本系统中对应 EPI 效应的 AuNPs 含量。该方法对目标 PSA 的分析具有良好的选择性和重现性。重要的是，通过对人血清标本和新生小牛血清稀释 PSA 标准品的分析，评估了 PEC 适体传感器的准确性和基质效应，与参考 PSA ELISA 试剂盒的结果吻合良好。
