Electrochemical Biosensing of Cortisol in a Hormone Tablet and Artificial Bodily Fluids

Abstract

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 μM. Moreover, the method demonstrated remarkable recovery values (99.90–102.06%) with relative standard deviations of 1.88–3.82% in real samples, which suggests its efficiency without being affected by the sample matrix.