Tuning the pure monoclinic phase of WO3 and WO3-Ag nanostructures for non-enzymatic glucose sensing application with theoretical insight from electronic structure simulations

Abstract

Here, we report the controlled hydrothermal synthesis and tuning of the pure monoclinic phase of WO3 and WO3-Ag nanostructures. Comparative electrochemical nonenzymatic glucose sensing properties of WO3 and WO3-Ag were investigated by cyclic voltammetry and chronoamperometric tests. We observed enhanced glucose sensing performance of WO3-Ag porous spheres as compared to bare WO3 nanoslabs. The sensitivity of the pure WO3 nanoslabs is 11.1 μA μM−1 cm−2 whereas WO3-Ag porous spheres exhibit sensitivity of 23.3 μA μM−1 cm−2. The WO3-Ag porous spheres exhibited a good linear range (5–375 μM) with excellent anti-interference property. Our experimental observations are qualitatively supported by density functional theory simulations through investigation of bonding and charge transfer mechanism of glucose on WO3 and Ag doped WO3. As the binding energy of glucose is more on the Ag doped WO3 (100) surface compared to the bare WO3 (100) surface and the Ag doped WO3 (100) surface becomes more conducting due to enhancement of density of states near the Fermi level, we can infer that Ag doped WO3 exhibits a better charge transfer media compared to bare WO3 resulting in enhanced glucose sensitivity in consistency with our experimental data.

Phase transformation in tungsten oxide nanoplates as a function of post-annealing temperature and its electrochemical influence on energy storage

“…The CV curve shows the quasi-rectangular nature due to the pseudocapacitive charge storage. The W80 electrode emphasizes the prominent reversible redox reaction, i.e., cathodic and anodic peaks arising from the reduction of W 6+ to W 5+ at the potential of À0.4 V to À0.5 V and À0.35 V to À0.45 V, respectively, which has shown by reaction (b):47 WO…”

Influence of defect structure on colour tunability and magneto optical behaviour of WO3 nanoforms

“…Annealing at 550 °C and above results in WO 3 having monoclinic structure [JCPDS card no. 43-1035 ( ref. 40 )].…”

Metal oxide nanostructures for sensor applications

“…Moreover, this material is widely used in solar photocatalysis [273,296,297], but it has also been demonstrated that this semiconductor material exhibits enhanced chemical sensing properties and is used in several sensing applications [298][299][300][301].…”