A new type of disposable flexible sensor for hydrogen peroxide (H2O2) detection was developed by in situ synthesis of copper-ruthenium bimetallic nanoparticles on a laser-induced graphene surface (Cu-Ru/LIG). The approach produced Cu-Ru/LIG via a solid phase transfer mechanism which loaded the metal precursor onto LIG, followed by laser scribing without demanding chemical vapor deposition or solution-based reactions. Cu-Ru/LIG showed a high electrocatalytic response toward H2O2 reduction at -0.4 V vs. Ag/AgCl. The sensor also showed good selectivity and reproducibility. This method provides an alternative route to easily synthesize various catalysts on conductive substrates for sensor applications.