Development of non-enzymatic electrochemical sensors for glucose and ascorbic acid

Abstract

Tremendous efforts have been directed towards the development of non-enzymatic sensors for the measurement of biomolecules such as glucose, ascorbic acid, uric acid, dopamine, etc. as it was established that the enzymatic sensors lack stability. Hence in this work, a more detailed study on non-enzymatic sensors was carried out for the measurement of glucose and ascorbic acid. Recently, nanomaterials based electrochemical sensors for the direct electrooxidation have been studied extensively due to their unique physical and chemical properties such as increased surface area, mass transport and catalysis. Copper and copper oxide based materials were reported to be potential candidates for the oxidation of glucose. Hence in this work, we have developed nanoporus copper oxide and copper oxalate modified copper electrode as well as copper oxide modified copper electrode for the quantitative determination of glucose. These modified electrodes were prepared by adopting a single step anodisation of copper in two different electrolytes. A prototype of the disposable sensor also was fabricated and tested with insulin pump which yielded good results. Similarly, for the quantitative determination of AA, the use of gold nanoparticles (AuNPs) attracted attention of different research groups due to the specific properties such as good conductivity, electrocatalytic behaviour and biocompatibility. Titanium dioxide nanotube arrays (TDNT) exhibit excellent properties such as large surface area, high orientation with uniformity and excellent biocompatibility, in addition to its ease of preparation. Making advantage of these characteristics of gold nanoparticles and titanium dioxide nanotube arrays, we developed ascorbic acid sensors by electrodeposition of gold nanoparticles on titanium dioxide nanotube arrays.