Novel Dry-Type Glucose Sensor Based on a Metal-Oxide-Semiconductor Capacitor Structure with Horseradish Peroxidase + Glucose Oxidase Catalyzing Layer

摘要

In this paper, we present a novel dry-type glucose sensor based on a metal-oxide-semiconductor capacitor (MOSC) structure using SiO_2 as a gate dielectric in conjunction with a horseradish peroxidase (HRP) + glucose oxidase (GOD) catalyzing layer. The tested glucose solution was dropped directly onto the window opened on the SiO_2 layer, with a coating of HRP + GOD catalyzing layer on top of the gate dielectric. From the capacitance-voltage (C-V) characteristics of the sensor, we found that the glucose solution can induce an inversion layer on the silicon surface causing a gate leakage current flowing along the SiO_2 surface. The gate current changes ΔI before and after the drop of glucose solution exhibits a near-linear relationship with increasing glucose concentration. The ΔI sensitivity is about 1.76nAcm~(-2)M~(-1), and the current is quite stable 20min after the drop of the glucose solution is tested.