Electrochemical determination of melatonin hormone using a boron-doped diamond electrode

In this study, a boron-doped diamond electrode was used for the electroanalytical determination of melatonin in the pharmaceutical tablet and urine samples by square-wave voltammetry. Melatonin yielded a well-defined voltammetric response in Britton-Robinson buffer, pH 3.0 at + 0.88 V (vs. Ag/AgCl). Using the optimal square-wave voltammetry conditions, the oxidation peak was used to determine melatonin in the concentration range of 5.0 × 107 M to 4.0 × 106 M (r = 0.998, n = 8), a detection limit of 1.1 × 107 M (0.025 μg/mL) and relative standard deviation was 2.06% at the 2.0 × 106 M level (n = 10). Recoveries of melatonin were in the range of 97.67–105%, for both tablet and spiked human urine samples.

► In this study, a BDD electrode was used for the electroanalytical determination of melatonin.
► Melatonin yielded a well-defined voltammetric response in BR buffer, pH 3.0 at + 0.88 V.
► The oxidation peak was used to determine melatonin in the concentration range of 5.0 × 107 to 4.0 × 106 M.