Highly Active Graphene Oxide-Supported Cobalt Single-Ion Catalyst for Chemiluminescence Reaction

Graphene- or graphene oxide (GO)-supported metallic nanoparticles and single metal atom as potentially effective catalysts for chemical reactions have recently received extensive research interests. However, metal utilization in nanoparticle catalysts is limited and metal atoms readily drift on the graphene surface and consequently form aggregated large particles, making practical applications limited. Here, we report metal ions directly immobilized on GO as a novel GO-supported single-ion catalyst for chemiluminecence (CL) reactions. It is found that GO-supported cobalt ions with good stability could catalyze strongly luminol–H₂O₂ and lucigenin–H₂O₂ CL reactions, accompanied by dramatically enhanced CL emission. Theoretical studies reveal that the coupling between Co²⁺ and GO induces effective polarization charges, improving chemical activity of the reaction site, which promotes the generation of intermediate radicals and accelerates the CL reactions. This work may be generalized to other GO-supported metal ions as catalysts for a wide range of chemical reactions. The developed GO-supported cobalt single-ion nanocomposites as nanointerfaces may find future applications in CL bioassays.