School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan 611731, China.
Institute of Electronic and Information Engineering of UESTC in Guangdong, Dongguan, Guangdong 523808, China.
Anal Chem. 2022 Mar 1;94(8):3526-3534. doi: 10.1021/acs.analchem.1c04508. Epub 2022 Feb 16.
Analysis of cortisol levels in human sweat is increasingly important as it can be a "stress biomarker" in stress-related disorders, giving real-time information about human health status. In this study, a portable 3D microfluidic origami biosensor based on a smartphone was developed for cortisol-level detection in human sweat. Molybdenum disulfide (MoS) nanosheet-mediated fluorescence resonance energy transfer (FRET) and fluorescently labeled aptamers were employed in the biosensing process. A multilayer-structured 3D origami microfluidic chip was fabricated and functionalized to facilitate low-volume perspired human sweat collection, transportation, and detection. The translatability of the biosensor was exhibited by the fluorescence analysis in a smartphone mounted in a custom-designed holder. The critical design parameters of the microfluidic origami biosensor, including the characterization of various paper substrates, the concentration of MoS nanosheets, and the incubation/reaction time, were adjusted to obtain an acceptable range for the assay dynamic range and limit of detection (LOD). Under optimum conditions, various doses of cortisol within the physiologically relevant range of 10-1000 ng/mL reported in human sweat were tested to evaluate the performance of the proposed biosensor. It displayed an LOD of 6.76 ng/mL at 3σ in artificial sweat, an analysis time of 25 min, and high selectivity. The performance of the proposed cortisol sensor was compared with an enzyme-linked immunosorbent assay (ELISA) for a spiked artificial sweat sample, and a correlation coefficient of 0.988 was found. The proposed biosensor also presented satisfactory results in the determination of the cortisol levels in a real human sweat sample. The resulting portable biosensor provides a rapid, low-cost, convenient, and non-invasive sensing solution for the point-of-care analysis of cortisol levels in sweat.
分析人体汗液中的皮质醇水平变得越来越重要，因为它可以作为应激相关疾病的“应激生物标志物”，提供有关人体健康状况的实时信息。在这项研究中，开发了一种基于智能手机的便携式 3D 微流控折纸生物传感器，用于检测人体汗液中的皮质醇水平。二硫化钼（MoS）纳米片介导的荧光共振能量转移（FRET）和荧光标记的适体被应用于生物传感过程中。多层结构的 3D 折纸微流控芯片被制造并功能化，以促进小体积的人体出汗收集、输送和检测。生物传感器的可翻译性通过智能手机上的荧光分析来展示，智能手机安装在定制设计的支架中。微流控折纸生物传感器的关键设计参数，包括各种纸张基底的特性、MoS 纳米片的浓度和孵育/反应时间，都进行了调整，以获得可接受的分析动态范围和检测限（LOD）范围。在最佳条件下，测试了人体汗液中生理相关范围内的各种皮质醇剂量（10-1000ng/mL），以评估所提出的生物传感器的性能。它在人工汗液中的检测限（LOD）为 6.76ng/mL（3σ），分析时间为 25 分钟，并且具有高选择性。所提出的皮质醇传感器的性能与酶联免疫吸附测定（ELISA）对人工汗液的加标样品进行了比较，发现两者的相关系数为 0.988。所提出的生物传感器在实际人体汗液中皮质醇水平的测定中也取得了令人满意的结果。该便携式生物传感器为汗液中皮质醇水平的即时检测提供了一种快速、低成本、方便和非侵入式的传感解决方案。
