NiCoP/g-C₃N₄ Nanocomposites-Based Electrochemical Immunosensor for Sensitive Detection of Procalcitonin

Herein, an ultra-sensitive and facile electrochemical biosensor for procalcitonin (PCT) detection was developed based on NiCoP/g-C₃N₄ nanocomposites. Firstly, NiCoP/g-C₃N₄ nanocomposites were synthesized using hydrothermal methods and then functionalized on the electrode surface by π-π stacking. Afterward, the monoclonal antibody that can specifically capture the PCT was successfully linked onto the surface of the nanocomposites with a 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and N-Hydroxysuccinimide (NHS) condensation reaction. Finally, the modified sensor was employed for the electrochemical analysis of PCT using differential Pulse Voltammetry(DPV). Notably, the larger surface area of g-C₃N₄ and the higher electron transfer capacity of NiCoP/g-C₃N₄ endow this sensor with a wider detection range (1 ag/mL to 10 ng/mL) and an ultra-low limit of detection (0.6 ag/mL, S/N = 3). In addition, this strategy was also successfully applied to the detection of PCT in the diluted human serum sample, demonstrating that the developed immunosensors have the potential for application in clinical testing.