title: Surface modification and bioconjugation of FeCo magnetic nanoparticles with proteins.
abstract: Magnetic Fe70Co30 nanoparticles with a cubic shape and a mean size of 15±1.5 nm were fabricated using a magnetron-sputtering-based gas phase condensation deposition method. The particles had a high saturation magnetization of 220 emu/g, which is much higher than that of commercially available iron oxide nanoparticles. The FeCo nanoparticles were modified by 3-aminopropyltriethoxy silane and subsequently activated by glutaraldehyde, leading to successful attachment of aldehyde groups onto nanoparticle surfaces. Three proteins, namely streptavidin, PAPP-A antibody and Nectin-4 antibody, were immobilized on glutaraldehyde activated FeCo nanoparticles, and their loading levels were quantitatively evaluated. Our results show that loading capabilities are 95 μg of streptavidin, 128 μg of PAPP-A, and 125 μg of Nectin-4 antibody per milligram of FeCo nanoparticles, and that the three immobilized proteins retain their binding bioactivity. The protein-FeCo conjugates may find valuable applications involving magnetic separation and purification of proteins and cells, and the magnetic detection of biomolecules.
authors.affiliation: Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455, USA; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455, USA.
authors.forename: Ying
authors.initials: Y
authors.lastname: Jing
authors.affiliation: Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455, USA.
authors.forename: Shihai
authors.initials: S
authors.lastname: He
authors.affiliation: Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455, USA. Electronic address: jpwang@umn.edu.
authors.forename: Jian-Ping
authors.initials: JP
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046, PR China. Electronic address: jpzhai@nju.edu.cn.
authors.forename: Jian-Ping
authors.initials: JP
authors.lastname: Zhai
mesh_terms: D000906:Antibodies / Q000737:chemistry / Q000378:metabolism*; D003035:Cobalt / Q000378:metabolism*; D007074:Immunoglobulin G / Q000737:chemistry; D007501:Iron / Q000378:metabolism*; D060328:Magnetic Phenomena; D058185:Magnetite Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008856:Microscopy, Fluorescence; D010316:Particle Size; D056951:Photoelectron Spectroscopy; D019809:Streptavidin / Q000378:metabolism*; D013499:Surface Properties
chemical_list: D000906:Antibodies; D007074:Immunoglobulin G; D058185:Magnetite Nanoparticles; D003035:Cobalt; D019809:Streptavidin; D007501:Iron
keywords: FeCo magnetic nanoparticles; Immobilization; Protein; Surface modification