Flexible non-enzymatic glucose strip for direct non-invasive diabetic management

Daily glucose measurements represent the routine practice for monitoring and managing diabetes. Current glucose/sugar analysis is dominated by intrusive finger-prick blood-based methods, which hinder the diabetic community in practical implementations. Nonenzymatic glucose sensors based on transition metals have shown robust glucose analysis performance in non-invasive biofluids. However, transition metals-based nonenzymatic glucose sensors are usually operated in an alkalic medium, thus strictly prohibiting further translational de-velopments. To resolve this issue, we propose a facile strategy to construct flexible nonenzymatic glucose strips (NEGS) for practical, non-invasive glucose analysis. The processed alkaline hydrogel patch was loaded onto the NGS to mimic the electrolyte medium for glucose reaction. The assembled hydrogel patch NEGS could detect glucose levels down to 1 mu M, with an excellent linearity response from 10 mu M to 3 mM and negligible current responses toward the excessive additions of potential interferences. As a proof of concept, these prepared devices were used for the glucose analysis of real sweat and saliva samples. Additionally, non-invasive biofluids of both healthy and diabetic subjects were synchronously compared, offering new insights into precision diabetic management by directly measuring the glucose levels in the non-invasive biofluidic samples without being cumbersomely correlated to blood glucose.