A renewable magnetic screen-printed electrode based on FeNi-loaded N–C nanotubes for omeprazole detection
Xinmei Qian, Chunxiang Li, Mingyu Zheng, Jinglun Wang, Haowen Huang, Keqin Deng
Abstract
In this work, a regenerable magnetic omeprazole electrochemical sensor was developed for the first time. Firstly, a magnetic bamboo-like nitrogen-carbon (N-C) nanotubes encapsulated with iron-nickel alloy (FeNi) nanoparticles (FeNi@N-CNTs) was prepared by a pyrolysis route. The characterization techniques including high resolution transmission electron microscopy (HRTEM), scanning electron microscope (SEM), X-ray diffraction (XRD), energy disperse spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS) revealed the surface morphology, structure, and chemical composition of the FeNi@N-CNTs. Cyclic voltammograms (CVs) and electrochemical impedance spectroscopy (EIS) results indicated that FeNi@N-CNTs had excellent conductivity and greatly facilitated the electron transfer. By applying FeNi@N-CNTs, a designed magnetic base support, and screen-printed electrode (SPE), a regenerable magnetic SPE was developed. The presence of FeNi@N-CNTs caused better omeprazole electron transfer kinetics at SPE surface. The FeNi@N-CNTs/SPE showed a linear detection range of 0.05–25.0 μM with a detection limit of 14 nM (S/N = 3) for detecting omeprazole. Due to the FeNi@N-CNTs adhering to SPE surface by magnetic control and easy disengagement from the electrode surface by magnetism, the proposed sensor was simple, regenerable, and cost-effective.