Optimized synergistic effects in sweat glucose detection with a Pt single-atom catalyst on NiO for fingertip wearable biosensors.

For the approximately 8.5 % of the global population living with diabetes, puncture-based glucose testing is often an unpleasant experience. Non-invasive sweat glucose testing not only reduces pain and the risk of wound infection but also offers a more suitable method for real-time glucose monitoring. In this study, we developed a fingertip wearable biosensor (FWB) capable of continuously measuring glucose levels in sweat, providing valuable data for assessing glucose concentrations in humans. We successfully synthesized NiO/Pt single-atom catalysts (NiO/Pt SAs) using a UV reduction technique, achieving a detection range of 5 μM to 2 mM that encompasses the full spectrum of physiological glucose levels. Additionally, incorporating 0.075 g of starch enhanced the hydrogel's water absorption and swelling properties, allowing it to absorb over 832 % of its dry weight without breaking, thereby improving sweat absorption efficiency. We also designed an annular microfluidic channel for rapid sweat transport. The circular design fits snugly on the fingertip surface, minimizing footprint and increasing comfort. This makes the device more stable in real-world use and minimizes the effects of external movements or environmental changes. Experimental results confirmed the feasibility of using the FWB to detect glucose in sweat samples from volunteers. We believe our research holds significant promise for advancements in sweat analysis and health monitoring, presenting a novel and efficient approach for continuous glucose monitoring.