title: Development of a stable dual functional coating with low non-specific protein adsorption and high sensitivity for new superparamagnetic nanospheres.
abstract: To overcome major challenges of non-specific protein adsorption on nanoparticles for nanosensing and nanodiagnosis, an efficient method for robust chemical modification was developed to achieve excellent specific biorecognition and long-term stability in complex biomedia. This method is demonstrated by a highly specific and sensitive immunoassay (IA), using superparamagnetic nanospheres (NSs) with high magnetite content. The non-specific protein adsorption on the NSs was suppressed dramatically when modified with dual functional poly(carboxybetaine methacrylate) (polyCBMA) via surface-initiated atom transfer radical polymerization (SI-ATRP) and chemically grafted with antibodies of the β subunit of human chorionic gonadotrop (anti-β-hCG). The response to hCG of IA NSs with polyCBMA coatings was highly consistent in either phosphate-buffered saline (PBS) or 50% fetal bovine serum (FBS), which is far less variable than the response of the IA NSs without polyCBMA coatings. After all, a very robust platform for IA NSs with excellent specific biorecognition was obtained. It is expected that this method for nanoparticle modification could be widely used in ultrasensitive nanosensing and nanodiagnosis in the future.
authors.affiliation: State Key Laboratory of Chemical Engineering, Department of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, People's Republic of China.
authors.forename: Xian'an
authors.initials: X
authors.lastname: Zhang
authors.forename: Weifeng
authors.initials: W
authors.lastname: Lin
authors.forename: Shengfu
authors.initials: S
authors.lastname: Chen
authors.forename: Hong
authors.initials: H
authors.lastname: Xu
authors.forename: Hongchen
authors.initials: H
authors.lastname: Gu
mesh_terms: D000327:Adsorption; D000906:Antibodies / Q000737:chemistry / Q000276:immunology; D006063:Chorionic Gonadotropin / Q000276:immunology; D006801:Humans; D008689:Methacrylates / Q000737:chemistry; D054118:Nanospheres; D011506:Proteins / Q000737:chemistry*
chemical_list: D000906:Antibodies; D006063:Chorionic Gonadotropin; D008689:Methacrylates; D011506:Proteins