Biomass electrooxidation-involved carbon radicals boost electrochemiluminescence

Developing new co-reactants with favorable thermodynamics to inhibit competing oxygen evolution reaction (OER) while achieving corresponding new radicals capable of efficiently exciting luminophores is a grand challenge for low-potential and sustained efficient anodic electrochemiluminescence (ECL). Herein, for the first time, we use thermodynamically favorable biomass, methanol, as a co-reactant and OER-inert Cu aerogels as co-reaction accelerators, achieving low-potential and stable emission in luminol ECL systems. In situ experimental monitoring and theoretical calculations reveal that the methanol oxidation reaction (MOR) efficiently inhibits OER, circumventing the instability and signal quenching associated with oxygen generation in luminol-H₂O systems. Specifically, MOR-derived carbon radicals (·CH₂OH) can subsequently trigger strong and stable ECL signals, achieving low-potential luminol emission. As a result, luminol-CH₃OH ECL systems exhibit a 36.5-fold enhancement in ECL intensity relative to luminol-H₂O systems, as well as excellent stability. We further demonstrate the universality of biomass electrooxidation-boosted ECL through successful extension to other biomass molecules, including glucose, furfural, and glycerol. Leveraging these unique advantages of luminol-biomass systems, a Cu-luminol-CH₃OH-based biosensor is constructed for detecting antibiotic resistance genes, along with high sensitivity and stability.