Guizhou Engineering Laboratory for Synthetic Drugs (Ministry of Education of Guizhou Province), College of Pharmacy, Guizhou University, Guiyang, 550025, China.
College of Chemistry and Materials Engineering, Guiyang University, Guiyang, 550005, China.
Anal Bioanal Chem. 2022 Apr;414(9):3033-3042. doi: 10.1007/s00216-022-03893-z. Epub 2022 Feb 21.
Nowadays, the epidemic, employment, and academic pressures are seriously affecting our physical and mental health. Herein, we designed a magneto-controlled photoelectrochemical immunosensor for noninvasive monitoring of salivary cortisol regarded as a pressure biomarker. A competitive immunoassay model was established by coupling bovine serum albumin-cortisol modified magnetic beads (MB-BSA-cortisol) with silver nanoclusters (Ag NCs)-labelled anti-cortisol antibody, and quantity analysis was operated by photoelectrochemical measurement of the CdS/Au electrode as an ion-exchange platform. Accompanying the formation of immune complexes, the carried Ag NCs were readily dissolved with nitric acid to produce abundant silver ions, which transferred to the electrode for ion-exchange reaction with CdS quantum dots to produce AgS, a new electron-hole capture site, leading to a decrease in the photocurrent intensity. The photocurrent signal gradually recovered with the increase of concentration of target cortisol, acquiring the signal-on mode competitive immunosensing system, which is propitious to the detection of small molecules. Within optimal conditions, this sensor had a satisfactory linear relationship in the range of 0.0001-100 ng mL with favorable repeatability, specificity, and acceptable method accuracy. The detection limit was as low as 0.06 pg mL. In addition, this strategy provided new thought for the test of other small-molecule analytes and immunosensor applied in the complex biological system.
如今，疫情、就业和学术压力严重影响着我们的身心健康。在这里，我们设计了一种磁控光电化学免疫传感器，用于非侵入式监测唾液皮质醇作为压力生物标志物。通过将牛血清白蛋白-皮质醇修饰的磁珠（MB-BSA-cortisol）与银纳米簇（Ag NCs）标记的抗皮质醇抗体偶联，建立了竞争性免疫分析模型，并通过 CdS/Au 电极的光电化学测量进行定量分析，作为离子交换平台。伴随免疫复合物的形成，所携带的 Ag NCs 很容易被硝酸溶解，产生大量的银离子，这些银离子转移到电极上与 CdS 量子点进行离子交换反应，生成 AgS，这是一个新的电子-空穴捕获位点，导致光电流强度降低。随着目标皮质醇浓度的增加，光电流信号逐渐恢复，获得信号开启模式的竞争性免疫传感系统，有利于小分子的检测。在最佳条件下，该传感器在 0.0001-100ng mL 的范围内具有令人满意的线性关系，具有良好的重复性、特异性和可接受的方法准确性。检测限低至 0.06 pg mL。此外，该策略为其他小分子分析物的测试和应用于复杂生物体系的免疫传感器提供了新的思路。
