Paper-based immunosensor with competitive assay for cortisol detection

Publication date: Available online 19 October 2019Source: Journal of Pharmaceutical and Biomedical AnalysisAuthor(s): Amara Apilux, Sirirat Rengpipat, Wilasinee Suwanjang, Orawon ChilapakulAbstractThe measurement of cortisol (stress hormone) is important for diagnosis and monitoring of stress-related diseases. A paper-based immunosensor with a competitive assay was developed for quick and easy detection of cortisol levels in serum. The paper-based sensor was fabricated using a simple and cheap wax printing method. Cortisol conjugated-BSA was immobilized on the paper’s surface in the detection zone for the competitive immunoassay. Anti-cortisol mAb-conjugated gold nanoparticles, as signal indicator, were used to detect cortisol in the sample. A 2-step procedure included applying the sample and washing for cortisol determination. The results showed that the device had the ability to differentiate cortisol levels into three ranges: < 25 µg/dL, 25-50 µg/dL and> 50 µg/dL by visual detection. The limit of detection determined by an image processing program was 21.5 µg/dL. This assay was successfully developed to detect cortisol in serum, and showed good recovery and precision. Our results correlated well with those obtained using an electrochemiluminescence method. This paper-based immunosensor provided a rapid and simple screening test for serum cortisol detection.Graphical abstract
Source: Journal of Pharmaceutical and Biomedical Analysis - Category: Drugs & Pharmacology Source Type: research