Rafiq Ahmad

Abstract There is a major challenge to attach nanostructures on to the electrode surface while retaining their engineered morphology, high surface area, physiochemical features for promising sensing applications. In this study, we have grown vertically-aligned ZnO nanorods (NRs) on fluorine doped tin oxide (FTO) electrodes and decorated with CuO to achieve high-performance non-enzymatic glucose sensor. This unique CuO-ZnO NRs hybrid provides large surface area and an easy substrate penetrable structure facilitating enhanced electrochemical features towards glucose oxidation. As a result, fabricated electrodes exhibit high sensitivity (2961.7 μA mM −1 cm −2 ), linear range up to 8.45 mM, low limit of detection (0.40 μM), and short response time (<2 s), along with excellent reproducibility, repeatability, stability, selectivity, and applicability for glucose detection in human serum samples. Circumventing, the outstanding performance originating from CuO modified ZnO NRs acts as an efficient electrocatalyst for glucose detection and as well, provides new prospects to biomolecules detecting device fabrication.

Unique and fascinating features of metal oxide nanostructures (MONs) have attracted considerable attention in recent years because without much effort, the MONs can be grown in many different nanoscale forms, thus allowing various novel devices of chemical and biological sensing to be fabricated. To improve the sensors performance by tailoring the properties of MONs through engineering of morphology, particle size, effective surface area, functionality, adsorption capability and electron-transfer properties have been extensively explored. This feature article collates the various MONs and their potential applications in the chemical and biological sensors for clinical and non-clinical applications.

Inkjet-printed copper oxide nanoparticles (CuO NPs) on silver electrodes were used to fabricate the nonenzymatic glucose biosensor. The inkjet-printed CuO NPs electrodes produced high and reproducible sensitivity of 2762.5 μAm M(-1) cm(-2) at an applied potential of +0.60 V with the wide linear-detecting range of 0.05-18.45 mM and the detection limit of ~0.5 μM (S/N = 3). The long-term stability and reproducibility of sensor in glucose electro-oxidation resulted from the chemical stability of CuO NPs and pore-like structure formed on Ag surface, which prevented the CuO NPs from conglomeration and the interference of oxygen in the air. Significantly, the effect of interfering species, such as AA, UA, and DA were negligible, whereas sugar derivatives (lactose, fructose, and mannose) show insignificant interference. Finally, the electrode was applied to analyze glucose concentration in human serum samples.