Single Co atoms in B-modulated graphitic carbon nitride realizing chemiluminescence enhancement in non-luminol system for folic acid detection

Low emission intensity hinders the broader application of chemiluminescence (CL) analysis, although it is regarded as a useful analytical technique owing to its several advantages, such as absence of background interference, ease of operation, and cost-effectiveness. Consequently, it is essential to develop effective sensitizers to improve CL performance. Single-atom catalysts (SACs) have emerged as a promising class of catalysts, exhibiting tunable properties through regulating the coordination environment and microenvironment surrounding the central single atoms. In this work, Co-N₄ sites anchored B-modulated graphitic carbon nitride (Co-B-C₃N₄ SACs) was designed as a CL catalyst to tailor the energy levels involved in the H₂O₂ adsorption pathway which was a critical step during the CL process. Experimental data and theoretical calculations synergistically proved that B-doping altered the electron distribution of Co atoms, thereby catalyzing the target CL reactions and promoting the generation of reactive oxygen species. The CL emission of NaHSO₃-H₂O₂ system was significantly enhanced by Co-B-C₃N₄ SACs. Furthermore, a CL sensor was constructed for folic acid detection, achieving a broad linear concentration range of 2.5–250 μM and a low detection limit of 41 nM.