Facile synthesis of MnO₂/carbon nanotubes decorated with a nanocomposite of Pt nanoparticles as a new platform for the electrochemical detection of catechin in red wine and green tea samples

Herein, we report a simple and facile synthesis strategy of MnO₂/carbon nanotubes decorated with a nanocomposite of Pt nanoparticles using a simple electrodeposition method. The Pt/MnO₂/f-MWCNT modified electrode were characterized by several analytical and spectroscopy techniques and were adopted as a composite for a novel catechin sensor. The as-prepared Pt/MnO₂/f-MWCNT modified glassy carbon electrode (GCE) exhibited a smaller peak potential separation (ΔE_p), and electron transfer kinetics during the oxidation reaction of catechin. This can be attributed to the larger effective surface area, greater porosity, and more reactive sites on the Pt/MnO₂/f-MWCNT-modified GCE. Notably, we achieved a very low detection limit (under optimized conditions) of catechin ca. 0.02 μM (S/N = 3); the linear range is 2-950 μM with excellent sensitivity. The real time application of catechin in red wine, black tea, and green tea samples with excellent performance. The proposed sensor was successfully developed and the advantages of low cost, ease of preparation, long-term stability, and good reproducibility were demonstrated which are superior to recently reported modified electrodes, thereby enabling practical industrial applications.