Publication

Abstract : The study aims to develop a highly sensitive and selective disposable non-enzymatic sensor for the non-invasive glucose detection from untreated saliva and urine samples. This was achieved using Nb2CTx MXene - graphene oxide - platinum - copper oxide nanocomposite modified screen printed carbon electrode. The MXene-GO composite was synthesised hydrothermally, and then copper oxide and platinum nanoparticles were chemically reduced and deposited on the composite. The XRD, EDAX, and XPS analyses confirmed the successful formation of the nanocomposite, and the SEM and TEM analyses revealed a cluster-like morphology of the platinum copper oxide on the niobium MXene-graphene oxide sheet. The Nb2CTx MXene-GO/Pt-CuO mixed with Nafion was drop-cast onto the working area of the screen-printed electrode. Two linear ranges, 0.01 to 1 mM and 1 to 15 mM, were observed with a sensitivity of 725.48±0.45 µA mM-1 cm-2 and 489.17±0.31 µA mM-1 cm-2, respectively. Excellent selectivity to glucose was observed in the presence of common biomolecules such as sugars, electrolytes, metabolites, amino acids, and proteins, evidenced by less than 5% current response compared to glucose. Reproducibility was confirmed with a relative standard deviation of 2.29% across 10 electrodes, and an excellent shelf life with a relative standard deviation of 2.14% over a month. The glucose concentrations measured using the developed sensor with untreated saliva and urine samples showed good agreement with clinical laboratory results, with a relative error of less than 3%. Overall, the sensor offers significant performance improvement compared to existing MXene-based nonenzymatic glucose sensors for non-invasive point-of-care testing.