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 (Nb
₂
O
₅
) nanosphere modified glassy carbon electrode (rGO-Nb
₂
O
₅
/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
$10~\mu \text{M}$
to
$300~\mu \text{M}$
for BPA, at a low electro-oxidation potential of 0.3 V with a sensitivity of
$0.153~\mu \text{A}/\mu \text{M}$
.cm
²
and limit of detection (LOD) of
$0.295~\mu \text{M}$
. Similarly, the sensor exhibits a wide dynamic range of detection from 10 nM to
$50~\mu \text{M}$
under a low electro-oxidation potential of 0.2 V with a low LOD of 2.709 nM and a sensitivity of
$11.5~\mu \text{A}/\mu \text{M}$
.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-Nb
₂
O
₅
/GCE sensor can be attributed to the synergistic effect of rGO, providing excellent electrical conductivity and the Nb
₂
O
₅
providing high electrostatic adsorption of the analyte via Nb
⁴⁺
/Nb
⁵⁺
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.