Peroxidase-like behavior, amperometric biosensing of hydrogen peroxide and photocatalytic activity by cadmium sulfide nanoparticles

A convenient solvothermal route has been developed for the synthesis of CdS nanoparticles (NPs) using a cadmium (II) complex [Cd(ACDA)(2)] of 2-aminocyclopentene-1-dithiocarboxylic acid (HACDA). Decomposition of the precursor complex has been carried out by ethylenediamine (EN), hexadecylamine (HDA) or dimethyl sulfoxide (DMSO). Structural analyses reveal the formation of crystalline nanoparticles with rod-like shape from EN and spherical shape from HDA or DMSO as solvents, while the optical properties suggest the quantum confinement by the nanoparticles. Superior photocatalytic activity towards the degradation of aqueous Rose Bengal (RB) solution has been achieved with the use of CdS NPs as photocatalyst under light irradiation. CdS NPs is found to possess peroxidase-like activity that can catalyze the oxidation of the peroxidase substrate 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H2O2 to produce a blue color reaction. CdS NPs anchored on glassy carbon (GC) electrodes have been prepared to study the electrocatalytic reduction of H2O2 in phosphate buffer solution. This modified electrode has also been used as amperometric biosensor for the detection of H2O2. (C) 2012 Elsevier B.V. All rights reserved.