Bimodal counterpropagating-responsive sensing material for the detection of histamine

Reliable and ultrasensitive quantification of harmful chemicals is essential to ensure food safety. In this study, a dual mode material for fast extraction and sensitive detection of histamine was developed. The novel sensing material was synthesized by coating a layer of molecularly imprinted polymers (MIPs) doped with silver nanoparticles (AgNPs) on the surface of upconversion particles (UCNPs). The novel material (UCNPs@MIPs-AgNPs) simultaneously possessed a positive surface-enhanced Raman scattering (SERS) response and negative fluorescence response. In the presence of histamine, the fluorescence intensity of UCNPs@MIPs-AgNPs was quenched gradually while the SERS intensity increased gradually. The limit of detection (LOD) and limit of quantitation (LOQ) of histamine were 0.009 mg L^-1 and 0.02 mg L^-1, and 0.04 mg L^-1 and 0.1 mg L^-1, respectively, under fluorescence mode and SERS mode. These results revealed that it is feasible to accurately detect histamine content by using the dual responsive material. The developed strategy integrates the advantages of upconverting nanotechnology, molecularly imprinted technology and SERS technology for highly specific enrichment and detection of histamine.