Dynamically regulating transient chemiluminescence of illuminated carbon nitride for simultaneous determination of ascorbic acid and dopamine

Developing a new strategy for a chemiluminescence (CL) sensor array to identify multiple biomarkers for psychiatric disorders simultaneously is a highly challenging task. This study designed a novel and straightforward strategy for simultaneous ascorbic acid (AA) and dopamine (DA) determination based on the interesting transient CL (TCL) kinetic curve tunability phenomenon on efficient graphite carbon nitride (CN) nanosheets. Advanced photoinduction strategies were introduced to synthesize light-illuminated CN nanosheets (L-CNNSs) as sensing materials with more negative reduction potential, excellent electron-hole separation, charge transfer capabilities, and high CL activity. Notably, using L-CNNSs as a sensing material could induce strong CL of alkaline lucigenin. This newly developed CL sensor exhibited high activity, excellent selectivity, and characteristic transient response toward AA and DA. Based on this finding, we developed a direct CL sensing platform for DA and AA discrimination in the urine of patients with mental disorders. Through many experiments, we attributed the CL recognition mechanism of the L-CNNSs/lucigenin system for DA and AA to the dynamic regulation of superoxide anions (O2·−) generation in the L-CNNSs solution. The different O2·− generation rates from L-CNNSs/lucigenin/AA and L-CNNSs/lucigenin/DA were regulated to obtain 'flash-type' and 'sustained-type' TCL curves, respectively, achieving simultaneous AA and DA discrimination and detection. This study provides insights for the simultaneous identification of multiple components based on CL sensors and offers new possibilities for practical analysis of sensor arrays.