Determination of nitrofurans in feeds based on silver nanoparticle-catalyzed chemiluminescence

A highly sensitive chemiluminescence (CL) method for the determination of nitrofurans (NFs) was developed based on the enhancement of CL intensity of luminol–H2O2–NFs system by silver nanoparticles (AgNPs). It was supposed that the oxygen-related radicals of OHradical dot and superoxide radical (O2radical dot−) could be produced when NFs reacted with H2O2. Furthermore, the enhancement mechanism was originated from the reinforcer of AgNPs, which could catalyze the generation of the OHradical dot radical. Then OHradical dot radicals reacted with luminol anion and HO2− to form luminol radical (Lradical dot−) and O2radical dot−. The excited state 3-aminophthalate anion was obtained in the reaction of Lradical dot− and O2radical dot−, which was the emitter (luminophor) in the luminol–H2O2 CL reaction system and the maximal emission of the CL spectrum was at 425 nm. The experiments of scavenging oxygen-related radicals were done to confirm these reactive oxygen species participated in the CL reaction. The limits of detection (LOD) (S/N=3) were 8×10−7 g mL−1 for furacilin, 8×10−8 g mL−1 for furantoin, 4×10−8 g mL−1 for furazolidone and 2×10−7 g mL−1 for furaltadone. The proposed method was successfully applied to the determination of NFs in feeds and pharmaceutical samples.