Manipal Journal of Science and Technology


Glucose sensors attract a great deal of attention due to the practical medical needs and applications. In this paper, we propose a simple methodology to modify semiconductor substrate such as indium tin oxide (ITO) in order to develop a non-enzymatic sensor for glucose detection. The proposed strategy involves a chemical modification of ITO electrode through electrodeposition of nickel and further by using electrochemical potential cycling in alkaline medium. Electrodeposition of nickel is carried out using two different methods. One involves the usage of nickel sulphamate electroplating bath in the absence of any template and the other comprises using a hexagonal lyotropic liquid crystalline phase as a template. This template is a two-component system, consisting of a surfactant viz., Triton X-100, and water containing the nickel salt used for electrodeposition. Electrochemical potential cycling in a pre-defined potential range results in the formation of redox active nickel hydroxide [Ni(OH)2] – oxy-hydroxide [Ni(OOH)] couple. The study of scan rate dependence on this redox behaviour reveals that the process of electron transfer is surface confined and diffusion controlled. These modified ITO electrodes are further investigated towards sensing of glucose, by monitoring the corresponding oxidation reaction in alkaline medium. We have also analyzed the effect of potential interferences such as dopamine and ascorbic acid along with a couple of other carbohydrates viz., sucrose, and lactose. Electrochemical techniques such as cyclic voltammetry (CV) and chronoamperometry (CA) are extensively used for the analysis. From the studies, we found out that the template deposited ITO electrodes provide a higher current density, better response, and a good stability when compared to Ni deposited electrodes without the template. These materials are highly stable, cost-effective involving a simple methodology for glucose detection. For comparison, we have also studied the sensing experiments using bare ITO, which does not show any catalytic activity towards glucose oxidation.

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