Construction of a Highly Selective Enrichment, Ionization, and Detection Platform Based on a Broad-Spectrum Antibody

Ambient mass spectrometry (AMS) allows direct analysisof variousraw food samples with minimal or no sample pretreatment, but the traceanalytes in complex food samples still have problems with limitations.In this work, we developed a platform based on coated stainless steelsheet spray mass spectrometry for fast, in situ, high-throughput,and high selectivity multiresidue analysis of fluoroquinolone drugs(FQs). The sensitivity of the platform was enhanced via coupling broad-spectrumantibodies against FQs to graphene oxide coated blade spray (CBS)-MSthrough a streptavidin-biotin (SA-biotin) interaction. Theprepared platform had sufficient loading capacity for SA (1.37 mg/piece)and the antibody (84.8 & mu;g/piece), which is greater than thatof physical mixing and the EDC/NHS covalent coupling strategy. Withsimplified sample pretreatment, this platform demonstrated comparablesensitivity to high performance liquid chromatography-mass spectrometry(HPLC-MS/MS) (0.08-0.16 ng/mL in phosphate-buffered salineand 0.21-0.32 ng/mL in diluted milk). Meanwhile, compared withHPLC-MS/MS, the method is rapid (enrichment: 10 min, detection: <1min) and acceptable recoveries (81.94-102.08%) can be obtained.The presence of analytes can be monitored by MS/MS spectra, and multipleanalytes can be measured simultaneously in a single assay. This studyis expected to provide a powerful and portable tool for rapid laboratoryanalysis and reliable screening in the field.