Development of oleic acid-functionalized magnetite nanoparticles as hydrophobic probes for concentrating peptides with MALDI-TOF-MS analysis

The oleic acid-functionalized magnetite nanoparticles (OA-Fe3O4) with mean diameter of about 15nm were synthesized through a low-cost, one-pot method and were designed as hydrophobic probes to realize the convenient, efficient and fast concentration of low-concentration peptides followed by MALDI-TOF-MS analysis. The capability of OA-Fe3O4 nanoparticles in concentration of low-abundance peptides from simple and complex solutions were evaluated by comparing them with a sort of C8-modified magnetic microspheres. Samples of standard peptide solution, protein digest solution and human serum were introduced in the evaluating process, and the OA-Fe3O4 nanoparticles exhibited good surface affinity toward low-concentration peptides