Ethylene glycol-protected magnetic nanoparticles for a multiplexed immunoassay in human plasma

The synthesis of short methoxyethyl-terminated ethylene glycol (MEG)-protected antibody-conjugated magnetic nanoparticles was investigated. It was shown that the magnetic nanoparticles (MNP) can significantly suppress nonspecific binding during the separation of of protein biomarkers in human sera. The results show that the suppression of nonspecific binding is highly dependent on MEG concentration. It was found that the specifity of high-affinity MNPs facilitates a rapid, sensitive, and accurate nanoparticle-based immunoassay, which requires a sample amount of only 0.1-1 μL plasma from a healthy individual to generate the target protein profiles.