The role of electrodeposition current density in the synthesis and non-enzymatic glucose sensing of oxidized zinc-tin hybrid nanostructures

This work reports the synthesis of different zinc-tin oxidized hybrid nanostructures and their non-enzymatic glucose sensing performance. Co-deposition of metallic Zn and Sn has been performed on copper (Cu) substrates at different current densities (15, 20, 25 & 30 mA/cm(2)). The electrodeposited Zn-Sn films have been hydrothermally treated at 95 degrees C for 12 h to obtain oxidized Zn-Sn hybrid nanostructures. XRD data confirmed the formation of zinc oxide (ZnO) and tin oxide (SnO2 and SnO) without exhibiting metallic phases. The FE-SEM and EDX results reveal that the current density is the controlling factor for surface morphology and Sn content (from 4 at% to 16 at%), respectively. Photoluminescence spectra also show that UV impurity peak intensity is enhanced with the increase in current density due to the rise in tin oxide content. The potential of oxidized Zn-Sn nanostructures have been explored for the non-enzymatic glucose sensing using electrochemical methods like cyclic voltammetry (CV) and amperometry. The response time of about 1 sec was observed for all the modified electrodes. The non-enzymatic glucose sensing performance for oxidized Zn-Sn electrodes is found to be strongly dependent on tin content and surface morphology. A higher glucose detection sensitivity of 2135 mu A mM(-1)cm(-2) (in the range of 0.5 mu M-0.1 mM) has been observed for oxidized Zn-Sn electrode prepared at 30 mA/cm(2). This study demonstrates the potential of oxidized Zn-Sn hybrid nanostructures toward non-enzymatic glucose sensing.