UV-Laser-Induced Graphene Electrodes with Triphase Interfaces for Manufacturable Flexible Oxidase Biosensing

Wearable biosensors based on oxidase enzymes offer promising avenues for continuous health monitoring but are limited by the low and fluctuating dissolved oxygen concentrations in biological fluids, which impair their accuracy and reliability. To address this challenge, triphase bioelectrodes leveraging atmospheric oxygen through engineered superhydrophobic interfaces have emerged as an attractive alternative. However, their widespread adoption in flexible devices has been hindered by complex fabrication processes, poor mechanical durability, and the lack of manufacturable, array-level platforms with consistent device-to-device performance. Here, we present a flexible triphase enzyme electrode fabricated via direct ultraviolet (UV) laser writing of three-dimensional porous laser-induced graphene (LIG) on polyimide substrates, enabling rapid, maskless, and programmable patterning of electrode arrays suitable for scalable production. The UV-derived LIG exhibits a compact and mechanically robust microstructure with hydrophobicity after PDMS treatment, facilitating efficient simultaneous uptake of atmospheric oxygen and liquid-phase analytes. This design significantly enhances enzyme reaction kinetics and sensor performance, while providing an engineering-oriented route toward reproducible, array-integrated flexible biosensors, demonstrating a scalable strategy for high-performance, flexible biosensors suitable for wearable healthcare applications.