DFT-assisted design inspired by loofah-derived biomass carbon decorated CoFe-CoFe2O4 conjugated molecular imprinting strategy for hazardous thiamphenicol analysis in spiked food

Abstract

Inspired by the porous microstructure of biomass carbon (BC) and the high adsorption properties of magnetic nanomaterials. A novel electrochemical sensor was developed for the selective assay of thiamphenicol (TAP) in fresh milk, honey, and meat samples by the preconcentration with magnetic molecularly imprinted polymer (MIP) based on differential pulse voltammetry (DPV). The magnetic MIP sensor (MIP/BC/CoFe-CoFe2O4/GCE) was fabricated by coupling CoFe-CoFe2O4 particles embedded loofah sponges derived BC with MIP film-decorated glassy carbon electrode (GCE). Theoretical simulation and quantum calculations based on density functional theory (DFT) accelerate the prediction and selection of rational functional monomers, as well as the ratio of template molecules to monomers. The surface structure, elemental composition, and electrochemical behavior were characterized by XRD, XPS, SEM, TEM, CV, and EIS, respectively. Various factors such as the amount of BC/CoFe-CoFe2O4, monomer/template ratio, polymerization cycles, pH value, elution time, and incubation time have been optimized to enhance the performance of the sensor. Under the optimal conditions, the current response intensities have three segments of good linear relationships with the TAP concentrations in the range of 0.01–2.0 µM (R2 =0.9930) and 2–400 µM (R2 =0.9955) as well as 400–5000 µM (R2 =0.9900) with an ultralow detection limit (LOD, S/N = 3) of 0.003 µM. Besides, the magneto-actuated electrochemical sensor exhibited outstanding analytical performance, i.e., excellent reproducibility and repeatability, ideal stability, and superior anti-interference ability. Moreover, the reliable recoveries (95.11%−105.00%) and the ideal relative standard deviations (RSDs) (1.2%−4.9%) for TAP determination in husbandry samples demonstrated that our developed sensor has good potential in the application.