High-Performance Black Phosphorus/Graphitic Carbon Nitride Heterostructure-Based Wearable Sensor for Real-time Sweat Glucose Monitoring

Abstract

Wearable, non-invasive glucose sensors capable of accurate and continuous monitoring are crucial for managing metabolic conditions, yet achieving high sensitivity and stability in these devices remains challenging. In this work, a black phosphorus/graphitic carbon nitride (BP-gCN) heterostructure is presented, engineered to leverage phosphorus-nitrogen interactions for enhanced nonenzymatic electrochemical glucose oxidation activity. Compared to pristine gCN, the BP-gCN heterostructure demonstrates a significantly improved electrochemical surface area and ≈2 fold reduction in the charge transfer resistance, achieving a remarkable glucose sensitivity of 4.75 µA mM⁻¹ cm⁻2 in artificial sweat. Density functional theory (DFT) calculations reveal stronger glucose adsorption and higher charge transfer on the BP-gCN heterostructure than the pristine gCN surface. These theoretical insights complement the experimental findings, highlighting the superior electrocatalytic performance of the heterostructure and the role of the oxidized BP surface. The developed BP-gCN sensor is integrated into a wearable platform with microfluidic layers and a near-field communication chip, forming a battery-free conformal skin patch. In vivo demonstrations confirmed its ability to enable real-time sweat glucose monitoring. This high-performance nonenzymatic wearable glucose sensor highlights the potential of heterostructure designs for seamless health management and next-generation biosensing platforms for personalized, continuous monitoring.