| Abstract
| - We report the synthesis, film formation, protein resistance, and specific antigen binding capability ofa carboxy-functionalized poly(ethylene glycol) alkanethiol [HOOC−CH2−(OCH2−CH2)n−O−(CH2)11−SH,n = 22−45]. Despite its polymeric character, the molecule is found to form a densely packed self-assembledmonolayer on polycrystalline gold, if adsorbed from dimethylformamide solution. Due to its chain lengthdistribution, the carboxy tailgroups are expected to be partially buried within the film and, thus, do notaffect the protein repulsive characteristics of the ethylene glycol moieties when exposed to fibrinogen andimmunoglobulin G (IgG). However, if activated by N-hydroxysuccinimide and N-(3-dimethylaminopropyl)-N-ethylcarbodiimide hydrochloride, antibodies can be covalently coupled to the monolayer. While resistanceto nonspecific fibrinogen and IgG adsorption is maintained for this biologically active layer, it exhibits highspecific antigen binding capacity. The performance of this highly selective surface is compared to that ofantibody films prepared by standard aminosilane chemistry.
|
