Continuous glucose monitoring using wearable non-enzymatic sensors in a physiological environment

Abstract

A novel non-enzymatic sensor has been developed for continuous glucose measurement in physiological body fluids using a Step-wise; amperometric method. Unlike; traditional nickel-based catalysts, this sensor overcomes challenges in biological and neutral pH environments. It utilizes a carbon fiber microelectrode modified with gold and nickel nanoparticles, reinforced by a biopolymer layer derived from quince seed mucilage (QSM). By applying a negative pretreatment potential step, hydroxide ions are locally generated, creating a partially alkaline environment that activates the nickel nanoparticles. Glucose concentration is determined by measuring the current at the electrocatalytic potential of nickel, which directly oxidizes glucose. To clean and reactivate the sensor, a positive pulse potential step is applied at the end of each cycle. The sensor exhibits high sensitivity (13.8 μA mM⁻¹.mm⁻²) and a low limit of detection (11.3 μM) in neutral pH (7.4). These results demonstrate the promising performance of the sensor for continuous glucose measurement in physiological body fluids. Using eco-friendly and biocompatible QSM as a reinforcing layer enhances its potential for biomedical applications. Additionally, a wearable compact electronic module was designed and fabricated to apply the potential, read the sensor's output currents, and monitor and record the results. The module's performance in measuring glucose in blood plasma is comparable to that of a commercial glucometer.