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 µM with a limit of detection (LOD) of 0.23 µM, and from 100 to 1000 µM with an LOD of 2.14 µM. 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.
Özyurt et al. (Mon,) studied this question.