Department of Engineering, University of Campania Luigi Vanvitelli, Via Roma 29, 81031 Aversa, Italy.
Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
Biosensors (Basel). 2024 Jul 19;14(7):351. doi: 10.3390/bios14070351.
Cortisol is a clinically validated stress biomarker that takes part in many physiological and psychological functions related to the body's response to stress factors. In particular, it has emerged as a pivotal tool for understanding stress levels and overall well-being. Usually, in clinics, cortisol levels are monitored in blood or urine, but significant changes are also registered in sweat and saliva. In this work, a surface plasmon resonance probe based on a D-shaped plastic optical fiber was functionalized with a glucocorticoid receptor exploited as a highly efficient bioreceptor specific to cortisol. The developed plastic optical fiber biosensor was tested for cortisol detection in buffer and artificial saliva. The biosensor response showed very good selectivity towards other hormones and a detection limit of about 59 fM and 96 fM in phosphate saline buffer and artificial saliva, respectively. The obtained detection limit, with a rapid detection time (about 5 min) and a low-cost sensor system, paved the way for determining the cortisol concentration in saliva samples without any extraction process or sample pretreatment via a point-of-care test.
皮质醇是一种经过临床验证的应激生物标志物，参与许多与身体对应激因素的反应相关的生理和心理功能。特别是，它已成为了解压力水平和整体健康状况的重要工具。通常，在临床中，皮质醇水平在血液或尿液中进行监测，但在汗液和唾液中也会记录到明显的变化。在这项工作中，基于 D 形塑料光纤的表面等离子体共振探针被用糖皮质激素受体功能化，该受体被用作皮质醇的高效生物受体。开发的塑料光纤生物传感器已在缓冲液和人工唾液中用于皮质醇检测进行了测试。生物传感器的响应对其他激素表现出非常好的选择性，在磷酸盐生理盐水缓冲液和人工唾液中的检测限分别约为 59 fM 和 96 fM。通过这种低成本的传感器系统，获得的检测限具有快速的检测时间（约 5 分钟），为通过即时检测无需任何提取过程或样品预处理来确定唾液样本中的皮质醇浓度铺平了道路。
