A minimally invasive sensing system based on hydrogel microneedle patches and Au/Cu2O nanospheres modified screen-printed carbon electrode for glucose monitoring in interstitial skin fluid

Glucose monitoring in interstitial skin fluid (ISF) has become a novel approach for diabetes management. In this paper, a minimally invasive sensing system consisted of methacrylated hyaluronic acid (MeHA) based microneedle patches and Au/Cu 2 O nanospheres modified screen-printed carbon electrode (SPCE) was designed for glucose monitoring in the ISF of living mice. The highly swellable and biocompatible MeHA microneedle patches can effectively extract ISF from the skin, barely cause pain to the living mice. The glucose level in the extracted ISF was detected via an enzyme-free electrochemical sensor using the Au/Cu 2 O nanospheres as the electrocatalyst. The doping of Au into Cu 2 O resulted in a highly conductive and active electrocatalyst for glucose oxidation, which improved the sensing performance of glucose sensor. A wide linear range (0.02 – 6 mM), low detection limit (0.018 mM), and high sensitivity (110.38 μA mM −1 cm −2 ) were obtained under the optimized condition. The obtained results exhibited a comparable trend to those obtained from commercial glucometers. We have combined successfully MeHA patches for ISF extraction with enzyme-free electrochemical glucose sensor. Therefore, this novel sensing system holds great potential for diabetes management in a minimally invasive manner.