Development of Dual-Gel System for Wearable Electrochemical Sensors

Abstract

With the innovation of materials and rapid development of wearable technology, wearable electronics—particularly textile-based systems—have broadened perspectives in health monitoring, therapy, and disease diagnosis.Bioelectronics interpret analyte information into real-time electrical signals with high sensitivity. Realizing the selective detection of analytes in biofluids often requires bioreceptors, such as enzymes, antibodies, and DNA, along with corresponding electrochemical detection techniques.Enzymatic sensors have relatively complex sensing structures among others. Enzymes function as biocatalysts at the sensing interface, facilitating electron transfer from analytes to the electrode surface. To enhance overall data acquisition, redox mediators are typically incorporated into these systems.Wearable bioelectronics are currently fabricated by depositing functional materials onto conformal flexible substrates using techniques such as spin coating, spray coating, printing, etching, and other technologies. However, seamlessly integrating multi-layer textile-based biosensors necessitates specific screen mesh and inkjet angles that ultimately limit the manufacturing process.Here, we propose a dual-gel system consisting of a base gel embedding functional materials (redox mediators and bioreceptors) and an encapsulation gel to stabilize the base gel while offering antifouling properties. The thin dual-gel film is fabricated through blade-casting followed by photo-initiated Chemical Vapor Deposition (piCVD) and can seamlessly adhere to various rough fabric surfaces. Moreover, this solvent-free process largely prevents bioreceptor degradation, promising better manufacturing sustainability.Glucose detection on flexible electrodes utilizing such a dual-gel system is exemplified as a proof-of-concept. This unique dual-gel system is expected to contribute to the development of textile-based electronics with greater versatility and improved sensing performance.