Xinyang Central Hospital , Xinyang 464000, China.
ACS Appl Mater Interfaces. 2018 Jan 31;10(4):3723-3731. doi: 10.1021/acsami.7b13557. Epub 2018 Jan 18.
The detection of biomarkers with high sensitivity and accuracy in real biosamples remains challenging. Herein, a universal spatial-resolved photoelectrochemical (PEC) ratiometry for biodetection of prostate-specific antigen (PSA) as model biomarker was designed for the first time based on a dual-electrode array modified by CdS@g-CN heterojunction coupled with CuS quantum dots (QDs) as signal amplification tags. Specifically, a new kind of photoactive material, the CdS@g-CN p-n heterojunction with high photoelectric conversion efficiency and good chemical stability, was synthesized and immobilized on two spatial-resolved electrodes (WE1 and WE2). After immobilizing gold nanoparticles and capturing PSA antibodies on the electrodes, WE1 incubated with various concentrations of PSA was taken as a working electrode, whereas WE2 with a fixed concentration of PSA was used as an internal reference electrode. Next, signal antibodies of PSA-labeled CuS QDs as PEC signal quenchers were immobilized on the electrodes to form a sandwich-type immunocomplex. With the aid of a multiplexed disjunctor, the PEC responses of the dual electrodes were recorded, and the PSA was quantified via the ratio values of photocurrent intensities from WE1 and WE2. Combining the fine PEC performance of the CdS@g-CN heterojunction with the superior quenching effect of CuS QDs in the spatial-resolved platform, the ratiometric system exhibits a linear range from 1.0 × 10 to 5.0 × 10 g mL with a limit of detection of 4.0 pg mL. The results demonstrated herein may provide a new pattern for biomarker detection with high accuracy and good specificity as well as satisfactory applicability in real biosamples.
在真实生物样本中，高灵敏度和准确性地检测生物标志物仍然具有挑战性。在此，首次设计了一种基于 CdS@g-CN 异质结与 CuS 量子点（QD）偶联作为信号放大标签的双电极阵列修饰的通用空间分辨光电化学（PEC）比率法，用于前列腺特异性抗原（PSA）作为模型生物标志物的生物检测。具体而言，合成并固定了一种新型光活性材料，即具有高光电转换效率和良好化学稳定性的 CdS@g-CN p-n 异质结，在两个空间分辨电极（WE1 和 WE2）上。在电极上固定金纳米粒子和捕获 PSA 抗体后，将 WE1 用不同浓度的 PSA 孵育作为工作电极，而 WE2 用固定浓度的 PSA 作为内参电极。接下来，将 PSA 标记的 CuS QD 作为 PEC 信号猝灭剂的信号抗体固定在电极上，形成三明治型免疫复合物。借助多路分离器，记录双电极的 PEC 响应，并通过 WE1 和 WE2 的光电流强度比值来定量 PSA。将 CdS@g-CN 异质结的精细 PEC 性能与空间分辨平台中 CuS QD 的优异猝灭效应相结合，该比率系统在 1.0×10 至 5.0×10 g mL 的线性范围内表现出良好的线性关系，检测限为 4.0 pg mL。本文的结果可能为具有高准确性和良好特异性以及在真实生物样本中令人满意的适用性的生物标志物检测提供一种新模式。
