A disposable amperometric sensor for rapid detection of serotonin in the blood and brain of the depressed mice based on Nafion membrane-coated colloidal gold screen-printed electrode

A new rapid, convenient and sensitive electrochemical method based on a Nafion membrane-coated colloidal gold screen-printed electrode (Nafion/CGSPE) was described for the determination of serotonin in the presence of high concentration of dopamine, ascorbic acid and uric acid. The electrocatalytic response of serotonin on the Nafion/CGSPE was evaluated by cyclic voltammetry (CV) in a 0.1 M phosphate buffer (pH 7.4) and the modified electrode exhibited better selectivity and higher sensitivity than the bare SPE. The linear calibration curve was obtained in the range of 2 × 10−8–5 × 10−4 M, with a correlation coefficient of 0.9969, and a detection limit of 5.0 nM in differential pulse voltammetry (DPV). We obtained linearity with correlation coefficient of 0.9971 for adding 0–4 × 10−6 M serotonin in the brain samples and 0.9978 in the blood samples. The adequacy of the developed method was successfully applied to the determination serotonin in the platelet-rich plasma (PRP) and in the brain homogenate of the mice. The correlation between the concentration of serotonin in the blood and brain of the depressed mice was studied.