Cubic MnSe2 nanoparticles dispersed on multi-walled carbon nanotubes: A robust electrochemical sensing platform for chloramphenicol

Abstract

A robust electrochemical sensor for chloramphenicol has been constructed by cubic MnSe 2 nanoparticles decorated on multi-walled carbon nanotubes. • MnSe 2 nanoparticles were firstly synthesized by a one-step hydrothermal process. • MnSe 2 /MWCNTs shows excellent synergistically catalytic properties towards CAP redox. • MnSe 2 /MWCNTs /GCE displays wide detection range for CAP sensing. • Detection of CAP in food and biological fluids was implemented. In this work, cubic MnSe 2 nanoparticles were firstly synthesized through a simple one-step hydrothermal procedure at low temperature using N 2 H 4 ·H 2 O as a reductant as well as MnCl 2 and Se powders as precursors. The crystalline structure, morphology, chemical composition, and element valence states of the synthesized samples were specifically investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), X-ray photoelectron spectra (XPS), and Raman spectroscopy. It was found that the MnSe 2 product mainly exists in a roughly cubic morphology with the sizes between 20 and 50 nm. In order to alleviate the aggregation, cubic MnSe 2 nanoparticles were further ultrasonically dispersed on the surface of multi-walled carbon nanotubes (MWCNTs) to achieve an improved stability structure denoted as MnSe 2 /MWCNTs. Compared with the single components, the MnSe 2 /MWCNTs composite displays enhanced electrochemical sensing signals for chloramphenicol (CAP) derived from the synergistic catalytic performance of the corresponding components. After optimization of electrochemical assay parameters, an assay range of 8.00–5000.00 μM and a limit of detection (LOD) with 2.00 μM for CAP were obtained using the MnSe 2 /MWCNTs-based sensor. Finally, the application of the resulting sensor for CAP detection in food and biological fluids was evaluated with recoveries between 94.70 and 106.70 %, demonstrating that MnSe 2 /MWCNTs could be served as a preeminent sensing platform. To the best of our knowledge, this is the first report on the fabrication of MnSe 2 -based composite for electrochemical sensing applications.