title: Functionalization of AlN surface and effect of spacer density on Escherichia coli pili-antibody molecular recognition.
abstract: The immobilization of antibodies to sensor surfaces is critical in biochemical sensor development. In this study, Jeffamine spacers were employed to tether Escherichia coli K99 pilus antibody to AlN/sapphire surfaces which may allow the antibody to freely reorient and potentially improving the antigen capture efficiency. Spacer density was one of the key parameters to be optimized in studying its effect on the immobilization of antibody. The spacer density was controlled by functionalizing AlN/sapphire surfaces with a mixed (3-glycidyloxypropyl)trimethoxysilane (GPTMS) and trichloro(1H,1H,2H,2H-perfluoroctyl)silane (FAS) self-assembled monolayer (SAM) through a step-wise method. Contact angle measurement and X-ray photoelectron spectroscopy (XPS) were used to characterize the surface coverage of GPTMS and surface chemical composition. Compared to spacer fully covered samples, the capture efficiency was improved by approximately 28% with optimal Jeffamine ED 600 spacer density, which depends on the spacer properties such as the number of monomer units and its size.
authors.affiliation: Department of Chemical Engineering and Materials Science, Wayne State University, 5050 Anthony Wayne Drive, Detroit, MI 48202, USA.
authors.forename: Ting
authors.initials: T
authors.lastname: Cao
authors.forename: Anfeng
authors.initials: A
authors.lastname: Wang
authors.forename: Xuemei
authors.initials: X
authors.lastname: Liang
authors.forename: Haiying
authors.initials: H
authors.lastname: Tang
authors.forename: Gregory W
authors.initials: GW
authors.lastname: Auner
authors.forename: Steven O
authors.initials: SO
authors.lastname: Salley
authors.forename: K Y Simon
authors.initials: KY
authors.lastname: Ng
mesh_terms: D000907:Antibodies, Bacterial / Q000276:immunology*; D001666:Binding Sites, Antibody; D004926:Escherichia coli / Q000276:immunology*; D010861:Fimbriae, Bacterial / Q000276:immunology*; D008855:Microscopy, Electron, Scanning; D013057:Spectrum Analysis / Q000379:methods; D013499:Surface Properties; D014965:X-Rays
chemical_list: D000907:Antibodies, Bacterial