Flexible molecularly imprinted glucose sensor based on graphene sponge and Prussian blue

To enhance the sensitivity of flexible glucose sensors made with 3-aminophenylboronic acid and pyrrole as functional molecules and a carbon tri-electrode as substrate, graphene sponge (GS) and Prussian blue (PB) were used to enhance the charge transfer between the molecularly imprinted cavities and the electrodes. Electrochemical impedance spectroscopy and cyclic voltammetry showed that modifying the electrode with GS and PB significantly reduced the charge transfer impedance and increased the redox current of the sensor. The sensor has a sensitivity of up to 25.81 µA⋅loge (µM)-1⋅cm-2 for the detection of glucose using differential pulse voltammetry in the range of 7.78 to 600 µM, with a low detection limit of 1.08 μM (S/N = 3). When the pH varies in the range of 5.5 to 7.5, the sensor maintains a certain level of stability for glucose detection. The presence of lactic acid, urea, and ascorbic acid had minimal impact on glucose detection by the sensor. After 20 days of storage at room temperature, the sensor maintains 80 % efficiency. This study supports the development of wearable glucose sensors with high sensitivity, specificity, and stability through molecular imprinting.