A gold nanoparticles deposited polymer microneedle enzymatic biosensor for glucose sensing

It is critical to monitor glucose level in the health management of diabetes patients. In this work, we developed a polylactic acid (PLA) based microneedle (MN) based glucose sensor. This PLA MN base was then coated with gold as the conductive layer, overoxidized polypyrrole (OPPy), gold nanoparticles (AuNPs), glucose oxidase (GOx), and Nafion. In vitro test, this glucose MN sensor showed a linear range from 0 to 2.6 mM with a sensitivity of 8.09 mu A/mM, limit of detection (LOD) of 40 mu M and not affected by ascorbic acid (AA), urea, glycine (Gly), acetaminophen (AP) in phosphate buffer solution,. The composite of OPPy and AuNPs improved the sensor sensitivity and GOx adhesive ability to the electrode. Nafion film protected the sensor from interfering substances. In the stability test, the sensor exhibited a stable monitoring sensitivity after 2 weeks. This work demonstrates this MN sensor has the potential to be applied in minimally invasive glucose monitoring. (C) 2020 Elsevier Ltd. All rights reserved.