A Hybrid Nanomaterial-Based Electrochemical Sensor for Melatonin Measurement in Human Saliva: A Diagnostic Tool for Anxiety Disorder

Abstract

Since the diagnosis of anxiety disorder is primarily based on questionnaires, accurate identification of the disorder can be challenging. Melatonin has been identified as a potential biomarker for the detection of anxiety disorders. By targeting this biomarker, it will be possible to get more accurate results and diagnose anxiety disorder more properly. In this study, a carbon screen-printed electrode modified with multi-walled carbon nanotube-gold-platinum (MWCNT-Au-Pt) nanocomposite-based electrochemical sensor was developed for the detection of melatonin. To enhance the sensor's performance, key experimental parameters-including the amount of MWCNT-Au-Pt nanoparticle and the pH of the solution-were systematically optimized. The sensor exhibited two linear response ranges for melatonin: from 0.5 to 50 & micro;M with a limit of detection (LOD) of 0.23 & micro;M, and from 100 to 1000 & micro;M with an LOD of 2.14 & micro;M. The sensor's specificity was evaluated in the presence of potential interfering substances. It was subsequently applied successfully to the detection of melatonin in 25 real human saliva samples. As a result, the first MWCNT-Au-Pt modified electrochemical sensor for melatonin detection, which will lead to proper anxiety disorder diagnosis, was fabricated.