Conjugation of Single-Chain Variable Fragment Antibody to Magnetic Nanoparticles and Screening of Fig Mosaic Virus by MALDI TOF Mass Spectrometry.

The ability of mass spectrometry for discrimination between protein and peptide masses which are unique to specific pathogens provides an accurate and fast method for the detection of different types of pathogens, especially viruses. Capsid proteins are specific to each virus and can be used as a biomarker for detection of this pathogen. On the other hand, single-chain variable fragment (scFv) antibodies have been recently used to enhance the accuracy of immunoassay techniques. So conjugation of mass spectrometry and scFv antibody provides a very accurate and fast method for the detection of viruses. In this report, for the first time, we have immobilized scFv antibody of fig mosaic virus (FMV) on the magnetic nanoparticles (MNPs) to extract the virus capsid protein from complex biological media and subsequently identified this protein through both its intact molecular mass and peptide mass fingerprint (PMF) by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS).