One-pot electrosynthesis of silver nanorods/graphene nanocomposite using 4-sulphocalix[4]arene for selective detection of oxalic acid

In this study, we reported an electrochemical synthesis of graphene (Gr) functionalized with silver nanorods (Ag NRs) using 3D surfactant 4-sulphocalix [4] arene (SCX) and silver nitrate (AgNO3) from an aqueous solution. SCX is acted as a soft template to form Ag NRs along with the Gr sheets. UV-Vis (UV-Vis), Fourier-transform infrared (FT-IR) and Raman spectroscopies have confirmed the formation of Gr with Ag NRs. In order to develop a selective electrochemical sensor for OA, Gr-Ag NRs nanocomposite coated glassy carbon electrode (GCE) was prepared and tested for OA oxidation. This new sensor (Gr-Ag NRs/GCE) exhibited high catalytic activity for OA in 0.1 M phosphate buffer and it showed a linear detection of OA from 3 to 30 mM with a detection limit of 0.04 mM. The effect of scan rate, pH and amount of catalysts were optimized. The interference of metal ions (Mg2+, Ca2+, Zn2+, Ni2+ and Co2+) and biomolecules such as ascorbic acid (AA) and uric acid (UA) were tested. Gr-Ag NRs/GCE is selectively responded to OA in the presences of these interferent ions. Moreover, the Gr-Ag NRs nanocomposite based sensor was successfully applied to detect OA in tap water samples with recoveries of 100 to 102%.Graphical abstract
Source: Sensors and Actuators B: Chemical - Category: Chemistry Source Type: research