Molecularly imprinted voltammetric sensor sensibilized by nitrogen-vacancy graphitized carbon nitride and Ag-MWCNTs...

The overdose of acetaminophen (AP) can cause serious acute liver injury even the irreversible liver necrosis. The quantitative detection of AP is of great significance not only for clinical applications but also for the quantity control of its pharmaceutical formulations. In this paper, a sensitive molecularly imprinted voltammetric sensor towards AP was constructed based on synergistic enhancement of nitrogen-vacancy graphitized carbon nitride (NV-g-C₃ N₄ ) and carboxylated MWCNTs loaded with silver nanoparticles (Ag-MWCNTs). The powder X-Ray diffraction spectrum, field emission scanning and transmission electron microscopes, cyclic voltammetry (CV), and electrochemical impedance spectrum were used to characterize the composites. The results show that NV-g-C₃ N₄ and Ag-MWCNTs closely embedded each other, forming loose porous hybrid structure by hydrogen bond. The prepared sensor molecular imprinting polymer (MIP)/C₃ N₄ /Ag-CNTs/GCE shows a strong synergistic enhancement of electroanalytical response by CV and differential pulse voltammetry (DPV) tests when compared with NV-g-C₃ N₄ /GCE, Ag-CNTs/GCE, and MIP/GCE. Through the optimization of the ratio of monomer and template, electropolymerization cycle, elution cycle, incubation time, and pH, linear ranges of 0.007-5 and 5-100 μM were found with the limit of detection of 2.33 nM by DPV. Moreover, its selectivity towards AP was satisfied when compared with detection towards ascorbic acid, dopamine, and glucose. The recovery range of 96.3%-100.5% was obtained in the spiked human serum and urine samples with the SD below 3.0%. In addition, the prepared sensor shows great detecting robustness with good anti-interference, reproducibility, and stability.