An Enzymatic Electrochemical Biosensing Interface Developed by The Laser-Induced Graphene Electrode

Laser-inducing provides a cost-effective, easily-manufacturable, and environment-friendly approach to directly transfer carbon-rich polymers into graphene materials, which attracts attention from various fields, such as sensors, electrocatalysts, micro-supercapacitors, etc. Laser-induced graphene (LIG) benefits from the intrinsic properties of graphene, for example, high conductivity, high electroactivity, and high specific area. In this work the potential of laser-induced graphene in constructing an enzymatic electrochemical biosensing interface is evaluated. Here, a laminar-structured laser-induced graphene material is fabricated by laser engraving with polyimide. After deposition of the electron mediator ferrocene, a conjugated enzyme complex of bovine serum albumin-glucose oxidase (BSA-GOx) is modified on the laser-induced graphene by cross-linking. The fabricated glucose oxidase/ferrocene/LIG (GOx/Fc/LIG) biosensor achieves high sensitivity of 11.3 & mu;A mM-1 cm-2), wide linear range of 0-11 mM, and low detection of limit of 0.04 & mu;M. The LIG electrodes exhibit high flexibility with bending angle as high as 60 & DEG; without observed conductivity change. The repeatability and robustness of the developed LIG biosensor in detection of real serum samples empower it with great potential in clinical implementation in the future. A high sensitivity and robust enzymatic electrochemical biosensing interface based on laser-induced graphene is developed by a combined low-cost fabrication strategy of ultraviolet laser pre-treatment and infrared laser defocused processing in together with conductive organic network-mediated conjugation of enzymes and electron mediators on the 3D porous graphene for enzyme immobilization.image