Synthesis of Pt doped TiO2 nanoparticles: Characterization and application for electrocatalytic oxidation of l-methionine

In this research, we reported a novel method for synthesis of Pt doped TiO2 nanoparticles (Pt–TiO2) by sol–gel assisted method. The synthesized Pt doped TiO2 nanoparticles were characterized using X-ray diffraction (XRD), transmission electronic microscopy (TEM) and FT-IR techniques. To investigate the catalytic efficiency of Pt–TiO2 nanoparticles, the electrooxidation of l-methionine (l-Met) using the deposited film of Pt doped TiO2 nanoparticles and carbon nanotubes composite on glassy carbon electrode (Pt–TiO2/CNT/GCE) was studied in buffer solution (pH 7.00) using cyclic voltammetry (CV). Bare GCE shows an ill-defined oxidation wave around 1.4 V for l-Met whereas Pt–TiO2/CNT/GCE shows a well-defined oxidation peak at 1.1 V. The modified electrode does not show any fouling effect toward the oxidation of l-Met. Amperometry method was used to determine l-Met in the concentration range of 0.5–100 μM with a detection limit of 0.1 μM (S/N = 3). The selectivity of the reaction has been assessed with no interference from tyrosine, lysine, cysteine, tryptophan, alanine and glutathione. The present modified electrode shows good recovery results for spiked l-Met in human blood serum sample.