An electrochemical sensor based on electro-polymerization of caffeic acid and Zn/Ni-ZIF-8-800 on glassy carbon electrode for the sensitive detection of acetaminophen.

A new electrochemical sensor was fabricated for the sensitive and selective detection of acetaminophen (AP), based on a bare glassy carbon electrode (GCE) modified with poly caffeic acid (PCA) and Zn/Ni-ZIF-8-800 using an electro-polymerization method. The carbon material of Zn/Ni-ZIF-8-800 derived from bimetal-organic framework was synthesized by one-step pyrolysis method. Then, the as-prepared materials and the corresponding fabricated sensors were fully characterized by XRD, FTIR, BET, SEM, TEM and XPS analyses. In addition, the electron transfer abilities of the modified sensors were investigated by CV and EIS. Subsequently, the parameters of polymerization time, pH value and scan rate were systematically studied and optimized. Under the optimum conditions, the desirable linear relationships were obtained between the peak current and the AP concentration at the PCA@ Zn/Ni-ZIF-8-800/GCE sensor with a detection limit of 0.0291 µM. The outstanding electrochemical performance of the proposed sensor can be attributed to the good electrocatalytic activity of PCA, the large surface area and high conductivity of Zn/Ni-ZIF-8-800 as well as the synergistic effect of PCA and Zn/Ni-ZIF-8-800. Moreover, the fabricated sensor was also successfully applied for the determination of AP in pharmaceutical dosage forms and human urine sample, and satisfactory recoveries were obtained.