High-Performance Amperometric Sensors Using Catalytic Platinum Nanoparticles-Thionine-Multiwalled Carbon Nanotubes Nanocomposite

Thionine (TH) adsorbed on multiwalled carbon nanotubes (MWCNTs) increases the load and dispersion of platinum nanoparticles (PtNPs) generated by chemical reduction of H2PtCl6 with NaBH4. Under the optimum conditions, the PtNPs-TH-MWCNTs/Au electrode electrocatalyzed the reduction and oxidation of H2O2 with high sensitivity, and after glucose oxidase (GOx) adsorption it responded to glucose concentration with a sensitivity of 0.14 AM(-1) cm(-2). The cyclic voltammetric cathodic peak current for NO2- reduction on PtNPs-TH-MWCNTs/Au responded linearly to NO2- concentration from 0.5 to 150 mu M, with a sensitivity of 5.52 AM(-1) cm(-2) and a detection limit of 0.2 mu M.