Electrochemical Glucose Sensing at a Multifunctional Hydrogel‐Modified Laser‐Induced Graphene Interface

This study presents a multifunctional laser‐induced graphene (LIG) interface for enzymatic glucose sensing with improved enzyme retention, fouling‐resistant behavior, and antibacterial potential. LIG surface was sequentially modified via electrodeposition of iridium (Ir) and platinum (Pt), forming bimetallic Ir–Pt heteronanostructures that exhibit strong peroxidase‐like catalytic activity. To enable stable enzyme immobilization, a multifunctional copolymer interface was constructed via co‐electropolymerization of sulfobetaine methacrylate (SBMA) and (3‐acrylamidopropyl)trimethylammonium chloride (APTAC) in the presence of glucose oxidase. A chitosan (CS)‐based immobilization was used as control platform. Importantly, this copolymer‐modified LIG platform integrates enzymatic sensing with fouling‐resistant and antibacterial potential functionalities within a single interface. CS‐ and copolymer‐modified electrodes exhibited broad linear detection ranges spanning three orders of magnitude (10 µM–7.5 mM and 0.5–10 mM, respectively), with sensitivities of 12.4 and 15.4 µA mM −1 cm −2 and detection limits of 8.14 and 6.55 µM, respectively. The Ir–Pt nanozyme layer significantly amplified the hydrogen peroxide‐mediated signal, delivering optimal analytical performance at +0.6 V versus Ag/AgCl, while operation at lower overpotentials reduced interference at the expense of sensitivity. The biosensing platforms maintained stable responses over 15 days of repeated measurements, demonstrating that electrosynthesized hydrogel/nanozyme architectures can serve as multifunctional biointerfaces for enzymatic sensing on LIG electrodes.