Development of electrochemical sensor system for detection of cortisol in saliva
Project no. 20213 · Status: Kapanmış · 2019
Summary
Cortisol is the main steroid-induced glucocorticoid hormone secreted from the adrenal cortex. In addition to the effects of the body on changing blood pressure, blood glucose level and carbohydrate metabolism in order to meet the changing needs in the sense of emotional or physical stress perception, it triggers many metabolic adaptation pathways such as stimulation of fatty acid secretion from fatty tissue and stimulation of amino acid mobilization from muscle proteins. It plays an important role in homeostasis of cardiovascular, immune, renal, skeletal and endocrine system. Cortisol release follows a 24-hour circadian rhythm. Half an hour after waking up in the morning to the highest level before going to bed is reduced to the minimum level. In addition to the day-night cycle, it may also be released by factors such as eating and physical activity.. In this study, we developed an impedimetric sensor system by using molecularly cortisol imprinted acrylamide polymers on fullerene modified carbon electrode to detect cortisol in real saliva samples. The polymer layer was formed on fullerene modified screen printed carbon electrodes with the ratio of 1:2 (cortisol:acrylamide) and ammonium persulfate (APS) was used as the initiator of polymerization. The sensor surface was investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and Scanning Electron Microscopy (SEM). Performances of the electrode were determined as follows; calibration curve was calculated between 0.5 nM to 64 nM, R2=0.9939, LOD and LOQ were 0.14 nM and 0.44 nM, respectively. Real human saliva samples were obtained from 15 participants between 25-32 ages regardless of gender. The samples, which were collected at least 30 minutes after waking up and the new sensor method analysis were compared tandem mass spectroscopy coupled liquid chromatography system (LC-MS/MS). The sensor analysis showed a significant correlation with LC-MS/MS results (R2=0.9727).