title: Nonspecific-adsorption behavior of polyethylenglycol and bovine serum albumin studied by 55-MHz wireless-electrodeless quartz crystal microbalance.
abstract: The nonspecific binding ability of polyethylenglycol (PEG) and bovine serum albumin (BSA) on modified and unmodified surfaces is quantitatively studied by a wireless-electrodeless quartz crystal microbalance (WE-QCM). PEG and BSA are important blocking materials in biosensors, but their affinities for proteins and uncoated substrates have not been known quantitatively. The WE-QCM allows quantitative analysis of the adsorption behavior of proteins on the electrodeless surfaces. Affinities of PEG, BSA, human immunoglobulin G (hIgG), and Staphylococcus protein A (SPA) for alpha-SiO(2)(quartz), Au thin film, PEG, and BSA are systematically studied by the homebuilt flow-injection system. PEG shows low affinities for the SiO(2) surface (K(A)=4.2x10(4) M(-1)) and the Au surface (K(A)=6.6x10(4) M(-1)), but BSA shows higher affinity for the SiO(2) surface (K(A)=1.4x10(6) M(-1)). Both PEG and BSA show low affinities for hIgG (K(A) approximately 1.5x10(5) M(-1)). However, the number of binding sites of PEG to hIgG is significantly larger than that of BSA, indicating that blocking for hIgG is favorably achieved by BSA, rather than PEG.
authors.affiliation: Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka, Japan. ogi@me.es.osaka-u.ac.jp
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Ogi
authors.forename: Yuji
authors.initials: Y
authors.lastname: Fukunishi
authors.forename: Hironao
authors.initials: H
authors.lastname: Nagai
authors.forename: Ken
authors.initials: K
authors.lastname: Okamoto
authors.forename: Masahiko
authors.initials: M
authors.lastname: Hirao
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Nishiyama
mesh_terms: D000327:Adsorption; D000818:Animals; D001665:Binding Sites; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D002417:Cattle; D003460:Crystallization; D055664:Electrochemical Techniques; D006046:Gold; D006801:Humans; D007074:Immunoglobulin G; D007700:Kinetics; D011092:Polyethylene Glycols; D011791:Quartz; D012680:Sensitivity and Specificity; D012710:Serum Albumin, Bovine; D012822:Silicon Dioxide; D013205:Staphylococcal Protein A; D013499:Surface Properties
chemical_list: D007074:Immunoglobulin G; D013205:Staphylococcal Protein A; D011791:Quartz; D012710:Serum Albumin, Bovine; D011092:Polyethylene Glycols; D006046:Gold; D012822:Silicon Dioxide