One-Pot Synthesis of rGO Supported Nb2O5 Nanospheres for Ultra-Selective Sensing of Bisphenol a and Hydrazine in Water Samples

Herein, we report a facile solvothermal assisted synthesis of reduced graphene oxide (rGO) supported niobium pentoxide (Nb2O5) nanosphere modified glassy carbon electrode (rGO-Nb2O5/GCE) sensor for the detection of persistent organic pollutants (POPs) like bisphenol A (BPA) and hydrazine (Hy). The as-fabricated sensor exhibits high sensitivity, selectivity and a wide dynamic range of detection from 10 mu M to 300 mu M for BPA, at a low electro-oxidation potential of 0.3 V with a sensitivity of 0.153 mu A/mu M.cm(2) and limit of detection (LOD) of 0.295 mu M. Similarly, the sensor exhibits a wide dynamic range of detection from 10 nM to 50 mu M under a low electro-oxidation potential of 0.2 V with a low LOD of 2.709 nM and a sensitivity of 11.5 mu A/mu M.cm(2) for Hy. Additionally, the sensor is found successful in sensing the BPA and Hy in drinking water and tap water samples. The excellent performance of the rGO-Nb2O5/GCE sensor can be attributed to the synergistic effect of rGO, providing excellent electrical conductivity and the Nb2O5 providing high electrostatic adsorption of the analyte via Nb4+/Nb5+ redox couple favouring electrooxidation process at the surface of the electrode. This proves the as-