Singh Naveen K, Chung Saeromi, Sveiven Michael, Hall Drew A
Department of Electrical and Computer Engineering, University of California-San Diego, La Jolla, California 92093, United States.
Department of Bioengineering, University of California-San Diego, La Jolla, California 92093, United States.
ACS Omega. 2021 Oct 11;6(42):27888-27897. doi: 10.1021/acsomega.1c03552. eCollection 2021 Oct 26.
There is a strong and growing need to monitor stress biomarkers for real-time emotional and wellness assessment. Toward this, we report a reagent-free electrochemical aptasensor with a nanocomposite antifouling layer for sensitive and continuous detection of cortisol in human serum. A thiolated, methylene blue (MB)-tagged conformation-switching aptamer was immobilized over a gold nanowire (AuNW) nanocomposite to capture cortisol and generate a signal proportional to the cortisol concentration. The signal is recorded through differential pulse voltammetry (DPV) and chronoamperometry. The aptasensor exhibited a sensitive response with 0.51 and 0.68 nM detection limits in spiked buffer and undiluted serum samples, respectively. Interference from other structurally similar analogs, namely, epinephrine and cholic acid, was negligible (<10%). The developed nanocomposite-based aptasensor showed excellent stability in undiluted human serum, outperforming several other nanocomposite materials even after prolonged exposure. This work lays the foundation for new biosensor formats such as implantable and wearable sensors.
实时监测应激生物标志物以进行情绪和健康评估的需求日益强烈。为此，我们报道了一种具有纳米复合防污层的无试剂电化学适体传感器，用于灵敏且连续地检测人血清中的皮质醇。一种巯基化、亚甲基蓝（MB）标记的构象转换适体固定在金纳米线（AuNW）纳米复合材料上，以捕获皮质醇并产生与皮质醇浓度成比例的信号。通过差分脉冲伏安法（DPV）和计时电流法记录信号。该适体传感器在加标缓冲液和未稀释血清样品中的检测限分别为0.51和0.68 nM，表现出灵敏的响应。其他结构相似的类似物，即肾上腺素和胆酸的干扰可忽略不计（<10%）。所开发的基于纳米复合材料的适体传感器在未稀释的人血清中显示出优异的稳定性，即使长时间暴露后也优于其他几种纳米复合材料。这项工作为可植入和可穿戴传感器等新型生物传感器形式奠定了基础。
