TiO2 anchored carbon fibers as non-invasive electrochemical sensor platform for the cortisol detection

An electrochemical immunosensor integrated on carbon yarns for non-invasive detection of cortisol is reported. The carbon yarns were integrated with TiO2 nanostructures for immobilizing cortisol specific antibodies. While the integration of TiO2 nanostructure was characterized using XRD and FE-SEM, the biorecognition of cortisol by antibodies modified yarns was investigated using voltammetric techniques (CV and DPV). The carbon yarn based immunosensor showed good sensitivity and is responsive over a broad-range of cortisol concentration (10 fg to 1 μg/mL). The efficacy of the cortisol sensing platform towards cortisol estimation in human sweat was evaluated and validated using commercially available chemiluminescence assay. The results demonstrated the excellent sensing performance of the TiO2 carbon fiber based flexible immunosensor system and its great potential in developing non-invasive POC sensor for human sweat cortisol detection.