Gelatin-Ionic liquid Based Platform for Glucose Detection

Herein, we have fabricated a novel platform consisting of gelatin B in ionic liquid [1-ethyl- 3-methylimidazolium chloride [C2mim][Cl] (ionic liquid, IL)] formed ionogels (Ig) by dissolution method and used it for glucose detection. The ionogels were deposited onto indium tin oxide (ITO) coated glass plate using drop casting technique. Glucose oxidase (GOx) was selected as a model enzyme to investigate its interaction with Ig/ITO electrode using electrochemical and optical methods. Structural and morphological studies of the Ig/ITO electrode were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and cyclic voltmmetry before and after GOx immobilization. It was found that [C2mim][Cl] enhanced electrocatalytic behaviour of the fabricated electrode which provided electron transfer rate constant as Ks ≈ 0.113 s-1. Response study of GOx/Ig/ITO bioelectrode as a function of glucose concentration was monitored. These gelatin-ionic liquid based bioelectrodes showed following results obtained from electrochemical technique linearity ≈ 1-20 mM, and low value of Michaelis-Menten constant, Km ≈ 0.174 mM with sensitivity ≈ 4.6µA mM-1 cm-2. In contrast, the optical detection of glucose exhibited linearity in the range of 6-20 mM, value of Km ≈ 3.8 mM with sensitivity 6.76 x 10-3 Abs/mM cm2. This clearly indicated that the prepared ionogel based electrodes will provide a promising platform for glucose detection.