Study On Immunochromatographic Assay Based On Up-conversion Fluorescent Nanoparticle For Chloramphenicol In Aquatic Products

Chloramphenicol(CAP)is a kind of broad-spectrum antibiotic,which is usually used unlawful for treatment and prevention of infectious diseases during aquatic animals breeding and storage process due to its good bactericidal effect and low price.Consumers who intakes the food containing CAP long-term may have adverse effects on their hematopoietic system.Therefore,to establish an efficient and rapid detection method for chloramphenicol residue is of great significance for ensuring food safety.Upconversion nanomaterials are not susceptible to environmental interference due to anti-stocks properties,and have high sensitivity,which has become a hot research topic in the field of fluorescent nanomaterial.In this paper,upconversion nanomaterials were prepared based on high temperature thermal decomposition,and characterized by scanning electron microscopy,transmission electron microscopy,energy dispersive X-ray spectroscopy and fluorescence spectroscopy.The results showed that the prepared nanoparticles are about 35 nm in diameter,and strong fluorescence intensity.The prepared upconverted nanomaterials were modified and functionalized by polyacrylic acid.Fourier infrared spectroscopy results showed that the surface of the nanoparticles has successfully been introduced carboxylic acid groups,resulting in good dispersibility in aqueous solution.The functionalized upconversion nanomaterials were used as fluorescent probes to fabricate a upconversion fluorescent immunochromatographic strip,and a new fluorescence detection method was developed to detect chloramphenicol.The target concentration can be determined by judging fluorescent intensity of the test line without any equipment.After optimization,the optimized mass ratio between CAP antibody and upconversion nanoparticles was determined to be 0.2 mg/5mg.The coating concentration in test line and control line was 1 mg/m L and 0.8 mg/m L,respectively.The sample dilution was determined to be PBST buffer,and the loading amount was10 μL.Under the optimal conditions,the detection limit was 100 ng/m L.This method was verified using eel as real sample.