Highly Sensitive and Rapid Determination of 3-amino-2- oxazolidinone in Animal Food by AuNPs/CMP Modified Screen Printing Electrode

In this manuscript, Au nanoparticles (AuNPs) and a nanospherical conjugated microporous polymer (CMP) were prepared and then modified on the surface of screen-printed carbon electrode (SPCE) to construct an electrochemical sensor for high sensitivity and rapid detection of 3-amino-2-oxazolidinone (AOZ). The preparation process of the materials and electrodes were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance (EIS), and the test conditions were optimized. Under optimal conditions, the oxidation peak current of AOZ and the concentrations show a wider linear relationship in the ranges of 1.0×10 −8 ∼1.0×10 −6 and 1.0×10 −6 ∼ 1.0×10 −4 mol/L ( R 1 2 = 0.996, R 2 2 = 0.998), respectively, and a lower detection limit which is as low as 3.3×10 −9 mol/L (S/N = 3) compared to existing methods. The reason for this result may be that CMP exhibited abundant porous structures and numerous active sites, which could significantly improve response sensitivity; AuNPs also possess high specific surface area and make the diffusion and transport of electrolyte ions easier. CMP-AuNPs nanocomposites greatly improved the electron transport rate, signal intensity and electroactive surface of SPCE, thereby improving the sensitivity of the sensor. It is worth noting that the sensor also has strong anti-interference ability, stability, and reproducibility. When applied to detect AOZ in real samples, it also showed good recovery rate. Compared with HPLC-MS/MS, the sensor also obtained good accuracy and consistency, which has great application potential for rapid on-site analysis and detection in animal-derived food not only for AOZ but also for Furazolidone (FZD).