Tungsten Carbide Nanotubes Supported Platinum Nanoparticles as a Potential Sensing Platform for Oxalic Acid

Supported tungsten carbide is an efficient and<br>vital nanomaterial for the development of high-performance,<br>sensitive, and selective electrochemical sensors. In this work,<br>tungsten carbide with tube-like nanostructures (WC NTs)<br>supported platinum nanoparticles (PtNPs) are synthesized and<br>explored as an efficient catalyst toward electrochemical<br>oxidation of oxalic acid for the first the time. The WC NTs<br>supported PtNPs modified glassy carbon (GC) electrode is<br>highly sensitive toward the electrochemical oxidation of oxalic<br>acid. A large decrease in the oxidation overpotential (220 mV)<br>and significant enhancement in the peak current compared to<br>unmodified and Pt/C modified GC electrodes have been<br>observed without using any redox mediator. Moreover, WC NTs supported PtNPs modified electrode possessed wide linear<br>concentration ranges from 0 to 125 nM and a higher sensitivity toward the oxidation of oxalic acid (80 nA/nM) achieved by the<br>amperometry method. The present modified electrode showed an experimentally determined lowest detection limit (LOD) of 12<br>nM (S/N = 3). Further, WC NTs supported PtNPs electrode can be demonstrated to have an excellent selectivity toward the<br>detection of oxalic acid in the presence of a 200-fold excess of major important interferents. The practical application of WC NTs<br>supported PtNPs has also been demonstrated in the detection of oxalic acid in tomato fruit sample, by differential pulse<br>voltammetry under optimized conditions.