title: Alkanethiolate self-assembled monolayers as functional spacers to resist protein adsorption upon Au-coated nerve microelectrode.
abstract: Alkanethiolate self-assembled monolayers (SAMs) of varied chain lengths were adsorbed upon Au-coated nerve microelectrodes and employed as protein-resistant spacers. The microelectrode spiraled as a cuff type can be used for restoring motor function via electrical stimulation on the peripheral nerve system; however, an increase of electrode impedance might occur during implantation. In this work, a thin-film SAMs treatment upon Au/polyimide (PI) surface of the microelectrode provided a hydrophobic characteristic, which retarded protein adsorption at the initial stage and subsequent pileup (or thickening) process. The protein-resistant effect exhibited comparable SAMs of different chain lengths adsorbed upon Au/PI surfaces. The increase of electrode impedance as a function of protein deposition time was mainly correlated with the addition of reactance that was associated with the pileup thickness of the deposited protein. Particularly, the SAMs-modified surface was capable to detach a significant portion of the accumulated protein from the protein-deposited SAMs/Au/PI, whereas the protein-deposited layers exhibited firm adhesion upon Au/PI surface. It is therefore very promising to apply thin-film SAMs adsorbed upon Au-coated surface for bioinvasive devices that have the need of functional electrical stimulations or sensing nerve signals during chronic implantation.
authors.affiliation: Institute of Biomedical Engineering, Department of Materials Science and Engineering, National Cheng Kung University Hospital, National Cheng Kung University, No. 1, University Road, Tainan 70101, Taiwan.
authors.forename: Cheng-Hung
authors.initials: CH
authors.lastname: Chang
authors.forename: Jiunn-Der
authors.initials: JD
authors.lastname: Liao
authors.forename: Jia-Jin Jason
authors.initials: JJ
authors.lastname: Chen
authors.forename: Ming-Shaung
authors.initials: MS
authors.lastname: Ju
authors.forename: Chou-Ching K
authors.initials: CC
authors.lastname: Lin
mesh_terms: D000327:Adsorption; D000473:Alkanes / Q000737:chemistry*; D000818:Animals; D001798:Blood Proteins / Q000737:chemistry*; D017097:Electric Impedance; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D007700:Kinetics; D008297:Male; D017933:Peripheral Nervous System / Q000502:physiology; D011817:Rabbits; D013057:Spectrum Analysis; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013696:Temperature
chemical_list: D000473:Alkanes; D001798:Blood Proteins; D013438:Sulfhydryl Compounds; D006046:Gold