Effect of transition metal doped ZnO coated on Al working electrode for K+ ion sensor

Abstract

Ni doped ZnO has been widely studied as a diluted magnetic semiconductor (DMS), but in this work we have shown its use as a biosensor. Now-a-days, electrochemical biosensors provide an attractive and affordable path to analyze biological samples by converting biological events directly to an electrical output. Alkali metal ions play a vital role in biological events and study of which is necessary to know the healthy functioning of human body organs. Potassium ion (K+) is one of the alkali metal ion in blood which needs regular monitoring. This motivated us to go for synthesis of ZnO and Ni doped ZnO by sol -gel method and later working electrodes were fabricated by coating the synthesized materials on Al substrate by Chemically Wet and Dry (CWD) method indigenously developed in our lab. The fabrication process was followed by insitu annealing of the sample electrodes at 450° C in presence of Nitrogen environment. The crystalline property of the synthesized materials was confirmed by XRD study. The Hall Effect study shows higher mobility and conductivity values for Ni doped ZnO in comparison to pure ZnO. The performance and response to various concentrations of KOH solution and PH level were experimentally studied by both electrodes separately considering Ag as reference electrode.The sensitivity of Ni doped ZnO coated Al electrode was found to be stable and longer sustainable than that of ZnO coated Al electrode in terms of potassium sensing.