One-Pot Synthesis of rGO Supported Nb2O5Nanospheres for Ultra-Selective Sensing of Bisphenol a and Hydrazine in Water Samples

Abstract

Herein, we report a facile solvothermal assisted synthesis of reduced graphene oxide (rGO) supported niobium pentoxide (Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> ) nanosphere modified glassy carbon electrode (rGO-Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> /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 μM to 300 μM for BPA, at a low electro-oxidation potential of 0.3 V with a sensitivity of 0.153 μA/μM.cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and limit of detection (LOD) of 0.295 μM. Similarly, the sensor exhibits a wide dynamic range of detection from 10 nM to 50 μM under a low electro-oxidation potential of 0.2 V with a low LOD of 2.709 nM and a sensitivity of 11.5 μA/μM.cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> 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-Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> /GCE sensor can be attributed to the synergistic effect of rGO, providing excellent electrical conductivity and the Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> providing high electrostatic adsorption of the analyte via Nb <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4+</sup> /Nb <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5+</sup> redox couple favouring electrooxidation process at the surface of the electrode. This proves the as-fabricated sensor as an ideal platform for developing simple electrochemical sensors for numerous bioanalytical applications.