Electrochemical biosensing of cortisol in a hormone tablet and artificial bodily fluids

This article describes a new voltammetric biosensor developed using a glassy carbon electrode functionalised with an anti-cortisol antibody to measure cortisol in a hormone tablet and artificial bodily fluids containing saliva, urine and sweat. The anodic signal of the produced biosensor at-60 mV linearly increased with the amount of cortisol. Cyclic voltammetry, scanning electron microscopy, energy dispersive X-ray spectroscopy, UV-visible spectrophotometry and Fourier transform infrared spectroscopy were performed to characterise the biosensor. Among the results, the biosensor detected 2 pM of cortisol in a linear range from 0.025 nM to 5 mu M. Moreover, the method demonstrated remarkable recovery values (99.90-102.06 %) with relative standard de-viations of 1.88-3.82 % in real samples, which suggests its efficiency without being affected by the sample matrix.