Porous hematite embedded C and Fe codoped graphitic carbon nitride for electrochemical detection of pineal gland hormone melatonin

Accurate detection of melatonin, a wide-spectrum antioxidant and vital pineal gland hormone, has high significance. Hence, nanomolar-level electrochemical determination of melatonin using a novel ternary nanocomposite with outstanding electrocatalytic activity is reported in this work. Porous flower-like hematite (α-Fe2O3) nanoparticles were embedded into carbon and iron codoped graphitic carbon nitride (C-Fe-gC3N4) sonochemically to prepare the ternary nanocomposite α-Fe2O3/C–Fe-gC3N4. A thermal polymerization approach was used for the preparation of C–Fe-gC3N4, and a hydrothermal method was utilized to synthesize the α-Fe2O3 nanoparticles. Detailed materials characterization was performed to examine the properties of synthesized materials, and various electrochemical investigations based on cyclic voltammetry and differential pulse voltammetry were conducted to analyze the electrochemical performance of prepared nanocomposite toward melatonin quantification. The melatonin sensor showcased ultra-low detection limit of 4 nM and excellent selectivity, stability, reproducibility, and repeatability. Practical feasibility of melatonin detection in tart cherry, human urine, and melatonin tablets was also validated in this work.