Selective detection of ascorbic acid with wet-chemically prepared CdO/SnO2/V2O5 micro-sheets by electrochemical approach

Abstract

Generally, ascorbic acid (AA) is a potent reducing and antioxidant agent that regulates in fighting against bacterial infections as well as detoxifying reactions, which is functioned in the formation of collagen in fibrous tissue, teeth, bones, connective tissue, skin, and capillaries. Up to date, electrochemical enzymatic sensor are significantly used for enzymatic AA detection that exhibits an excellent selectivity, high reliability and handled under physiological conditions. However, considering some intrinsic dis-advantages of using enzymes, such as high fabrication cost and poor stability, non-enzymatic AA sensors have attracted increasing research interest in recent years owing to their low cost, high stability, fast response, and low detection limit. Moreover, the development of nanotechnology has also offered new opportunities to develop the nanostructured sensor probes for enzyme-less AA sensing applications. With beneficial advantages, ternary-doped metal oxides have gathered an extensive effort in the development of cost-effective sensors with high stability, sensitivity and quick response for the determination of selective AA by enzyme-free detection. In this approach, the mixed metal oxides of CdO/SnO2/V2O5 micro-sheets (MSs) were prepared by facile wet-chemical method in alkaline phase at low temperature. Later, it was subjected to detail characterize by using various methods such as XPS, FESEM, EDS, and XRD. The slurry of prepared MSs in ethanol was deposited initially onto the surface of glassy carbon electrode (GCE) to make a thin film with conducting nafion (5% suspension in ethanol) adhesive to result the working electrode of proposed AA sensor probe. The sensor sensitivity (21.3354 μA μM−1 cm−2) is calculated by using the slope (0.6742 μA μM−1) of the calibration curve by considering the active surface area of GCE (0.0316 cm2) in the linear dynamic range (LDR; 0.1 nM to 0.01 mM). The limit of detection (LOD) (98.64 ± 4.98 pM) is obtained from the calibration curve. The proposed AA electrochemical sensor exhibits short response time, good reproducibility and successive outcome during the investigation of the real biological samples. The development of enzyme-free AA sensor by using CdO/SnO2/V2O5 MSs onto GCE is simple as well as reliable and practically able to detect the biological stuffs for the safety of human health in the field of biomedical and sensor technology.