Triplex electrochemical sensing of dopamine and antipsychotic drugs enabled by palladium and phosphorus co-doped graphitic carbon nitride.

Chlorpromazine (CPZ) and clozapine (CLZ) are widely used antipsychotics that exert therapeutic effects primarily through dopamine (DA) receptor antagonism. Simultaneous monitoring of these drugs alongside DA in biological fluids is crucial to avoid adverse effects in clinical practice. In this work, we developed an electrochemical sensor based on Pd and P co-doped g-C3N4 nanosheets for the synchronous detection of CPZ, CLZ, and DA. The synergistic incorporation of P and Pd effectively modulates the electronic structure by narrowing the bandgap and reducing charge transfer resistance, thereby significantly accelerating electron transfer kinetics during the redox reactions of the analytes. The sensor exhibited broad linear detection ranges of 0.02-100.00 μM for CPZ and CLZ, and 0.05-250.00 μM for DA, with detection limits of 5 nM, 5 nM, and 10 nM, respectively. Compared with single-analyte detection, the simultaneous approach offers overall comparable or improved accuracy and reproducibility. The sensor also displayed high specificity, with minimal interference (<5%) from coexisting biological species, and was successfully applied to the analysis of real biological samples. This Pd/P-g-C3N4-based electrochemical sensing platform offers a promising tool for personalized therapeutic drug monitoring and real-time pharmacokinetic-pharmacodynamic analysis in clinical settings.