Control of sensitivity in metal oxide electrolyte gated field-effect transistor-based glucose sensor by electronegativity modulation

In this study, the sensitivity of electrolyte-gated field-effect transistor-based glucose sensors using oxide semiconductor materials was controlled via electronegativity modulation. By controlling the enzymatic reaction between glucose and glucose oxidase, which is affected by the surface potential, the sensitivity of the glucose sensor can be effectively adjusted. To evaluate the sensitivity characteristics of the glucose sensor according to electronegativity control, devices were fabricated based on InO through Ga and Zn doping. The results confirmed that the specific sensitivity range could be adjusted by increasing the electronegativity. In addition, density functional theory calculations, confirmed that the attachment energy of the surface-functionalized material and the enzyme binding energy in the surface-functionalized thin film can be modulated depending on the electronegativity difference. The dissociation constant was controlled in both directions by doping with metal cations with larger(Ga, 1.81) or smaller(Zn, 1.65) electronegativities in InO(In, 1.78). We expect that this study will provide a simple method for the gradual and bidirectional control of the glucose sensitivity region.