Flow injection chemiluminescence sensor based on core–shell magnetic molecularly imprinted nanoparticles for determination of chrysoidine in food samples

A novel flow injection chemiluminescence (CL) sensor for the determination of chrysoidine (CSD) using magnetic molecularly imprinted polymers (MMIPs) as recognition element is reported. The MMIPs were polymerized at the surface of Fe3O4@SiO2 magnetic nanoparticles (MNPs) using methyl methacrylate (MAA) and ethylene glycol dimethacrylate (EGDMA) as functional monomer and cross-linking agent, respectively. The MMIPs were characterized by TEM, XRD, dynamic adsorption and static adsorption tests. Because of the imprinted sites almost situated at the surface of imprinting products, the MMIPs had excellent adsorption capacity, specific recognition and direct magnetic separation in samples. Then the synthesized CSD-MMIPs were employed as recognition element by packing into flow cell to establish a new flow injection CL sensor. The CL intensity responded linearly to the concentration of CSD in the range of 1.0 × 10−4–2.0 × 10−6 mol L−1 with a detection limit of 6.19 × 10−7 mol L−1. The relative standard deviation (RSD) for the determination of 2.0 × 10−6 mol L−1 of CSD was 2.3% (n = 11). The sensor is reusable and has a great improvement in sensitivity and selectivity for CL analysis. As a result, the novel MMIP-CL sensor had been successfully applied to the determination of CSD in food samples.