Study On Upconversion Fluorescence Immunoassay For Detection Of Bisphenol A And Dimethyl Phthalate

In our study,NaYF4:Yb,Tm and NaYF4:Yb,Er upconversion nanomaterials(UCNPs)were used as the fluorescence signal labels,the magnetic polystyrene microspheres(MPMs)were chosen as separation mediums.An upconversion nanoparticles-based fluorescence immunoassay in combination with magnetic separation was proposed to detect bisphenol A(BPA)and a multicolor upconversion nanoparticles-based fluorescence immunoassay in combination with magnetic separation was proposed for the simultaneous detection of BPA and dimethyl phthalate(DMP).The coating antigen(BHPVA-OVA)was prepared via an active ester method.The oil-soluble upconversion nanoparticles with uniform particle size were synthesized by thermal decomposition method.The water-soluble upconversion nanoparticles were synthesized by carboxyl group modification on the surface of oil-soluble upconversion nanoparticles by ligand exchange method.The water-soluble upconversion nanoparticles were conjugated with the anti-BPA antibody to prepare the signal probe and the carboxyl-functionalized magnetic polystyrene microspheres were conjugated with the coating antigen to prepare the capture probe by activated ester methods.Under optimal conditions,the upconversion nanoparticles-based fluorescence immunoassay in combination with magnetic separation for detection of BPA was successfully established.The detection limit of this method was 0.1 ?g L-1,the linear detection range was from 0.1 to 500 ?g L-1.There was no cross-reaction with other analogues,indicating good specificity of this method.The results of the spiked samples and real water samples by the proposed fluorescence immunoassay were in good agreement with the results obtained by HPLC,indicating good accuracy and practicability of the proposed method.Two kinds of upconversion nanomaterials with non-overlapping fluorescence spectra were synthesized by thermal decomposition method,and they were conjugated with anti-BPA antibody and the anti-DMP antibody respectively to prepare signal probes after carboxyl modification.Magnetic polystyrene microspheres were conjugated with their owner coating antigens to prepare two capture probes.Two single detection systems of BPA and DMP were formed a detection system to achieve simultaneous detect BPA and DMP.The test wavelengths were set at 483 nm for BPA and 553 nm for DMP,respectively.Under optimal conditions,a multicolor upconversion nanoparticles-based fluorescence immunoassay in combination with magnetic separation for the simultaneous detection BPA and DMP was successfully established.The detection limit of BPA was 0.1 ?g L-1,and the linear range was from 0.1 to 500?g L-1.The detection limit of DMP was 1 ?g L-1,the linear range was from 1 to 1000 ?g L-1.This method has no cross-reactions with the structural analogues of BPA and DMP.The results of the spiked and real water samples by the proposed fluuorescence immunoassay were in good agreement with the results obtained by HPLC and GC-MS.