Room-Temperature Aqueous Synthesis of Pd-Core Pt-Shell Nanowires for Electrochemical Non-enzymatic Sweat Glucose Sensing

 Developing non-invasive, highly sensitive glucose monitoring system is crucial for the effective diagnosis and management of diabetes. However, conventional enzyme-based sensors suffer from limited long-term stability and environmental vulnerability, while most reported non-enzymatic sensors require alkaline conditions over pH 9. In this study, an electrochemical non-enzymatic glucose sensor based on Pd-core Pt-shell nanowires (Pd@Pt NWs) sequentially drop-cast onto a conductive polymer (PEDOT:PSS) layer on a gold-platinum bimetallic three-electrode system is presented, providing a stable and highly sensitive platform tailored for sweat conditions. Highly crystalline core-shell bimetallic nanowires were successfully synthesized via a facile approach in an aqueous solution at room temperature without any high-temperature, high-pressure treatments, or organic solvents. The unique core-shell nanowire structure induces lattice tensile strain, optimizing the surface electronic structure of the catalyst. Consequently, the developed patch-type sensor exhibits outstanding performance at physiological pH, demonstrating high sensitivity (56.06 μA mM^-1 cm^-2), a low detection limit (40.26 μM), and high selectivity against common interferents in sweat and other sugars. Furthermore, it displays remarkable long-term stability over a 60-day period, maintaining a consistent current density with a minimal standard deviation (5.68 μA cm^-2), thereby enabling reliable glucose detection within the typical concentration range found in human sweat. These findings provide a user-friendly and robust electrode platform, offering great potential for advancing non-invasive, in situ wearable continuous sweat glucose monitoring systems.