Electrochemical study of novel nanostructured In2S3 and its effect on oxidative damage to DNA purine bases

Abstract

Novel nanostructured In2S3 was synthesized using a one-step solution growth approach in various indium nitrate to thioacetamide ratio and in absence of surfactants. Morphology studies showed the flower-like structure of the nanomaterials obtained. For the electrochemical study, In2S3 nanomaterials were immobilized at the surface of the glassy carbon electrode. Modified glassy carbon electrodes were then characterized by cyclic voltammetry of the three redox systems: [Ru(NH3)6]3+/[Ru(NH3)6]2+, [Fe(CN)6]3−/[Fe(CN)6]4−, and hydroquinone/quinone. The calculated standard electron transfer rate constants were in agreement with those calculated from electrochemical impedance measurements. Electrochemical impedance spectra measured at different potential values were used to study semiconducting properties of In2S3 samples. Analysis showed n-type semiconductor behavior for all In2S3 samples. The donor density (∼10−18cm−3) and flat band potential (∼−0.8V) were in agreement with those reported for indium contained semiconductors. As the semiconducting and photocatalytic properties are related to production of the free radicals able to damage DNA, the effect of In2S3 exposed to UV radiation on DNA bases was studied. In2S3 nanomaterials in the dispersion medium enhanced the production of free radicals and the oxidation stress and caused significant damage to DNA bases. Our results show that In2S3 nanomaterials exhibit good semiconducting properties and are also efficient photocatalysts.