title: Electroactive SWNT/PEGDA hybrid hydrogel coating for bio-electrode interface.
abstract: Electric interface between neural tissue and electrode plays a significant role in the development of implanted devices for continuous monitoring and functional stimulation of central nervous system in terms of electroactivity, biocompatibility and long-term stability. To engineer an interface that possesses these merits, a polymeric hydrogel based on poly(ethylene glycol) diacrylate (PEGDA) and single-walled carbon nanotubes (SWNTs) were employed to fabricate a hybrid hydrogel via covalent anchoring strategy, i.e., self-assembly of cysteamine (Cys) followed by Michael addition between Cys and PEGDA. XPS characterization proves that the Cys molecules are linked to gold surface via the strong S-Au bond and that the PEGDA macromers are covalently bonded to Cys. FTIR spectra indicate the formation of hybrid hydrogel coating during photopolymerization. Electrochemical measurements using cyclic voltammetry (CV) and impedance spectrum clearly show the enhancement of electric properties to the hydrogel by the SWNTs. The charge transfer of the hybrid hydrogel-based electrode is quasi-reversible and charge transfer resistance decreases to the tenth of that of the pure hydrogel due to electron hopping along the SWNTs. Additionally, this hybrid hydrogel provides a favorable biomimetic microenvironment for cell attachment and growth due to its inherent biocompatibility. Combination of these merits yields hybrid hydrogels that can be good candidates for application to biosensors and biomedical devices. More importantly, the hybrid hydrogel coatings fabricated via the current strategy have good adhesion to the electrode substrate which is highly desired for chronically implantable devices.
authors.affiliation: School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, China.
authors.forename: Lei
authors.initials: L
authors.lastname: He
authors.forename: Demeng
authors.initials: D
authors.lastname: Lin
authors.forename: Yanping
authors.initials: Y
authors.lastname: Wang
authors.forename: Yinghong
authors.initials: Y
authors.lastname: Xiao
authors.forename: Jianfei
authors.initials: J
authors.lastname: Che
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000138:chemical synthesis* / Q000378:metabolism / Q000494:pharmacology; D032701:Biomimetics / Q000379:methods*; D015374:Biosensing Techniques / Q000379:methods*; D003543:Cysteamine / Q000737:chemistry / Q000378:metabolism*; D004583:Electrons; D006046:Gold / Q000737:chemistry / Q000378:metabolism; D020100:Hydrogels / Q000737:chemistry / Q000378:metabolism*; D008027:Light; D008839:Microelectrodes; D008853:Microscopy; D037742:Nanotubes, Carbon / Q000737:chemistry*; D009474:Neurons / Q000166:cytology / Q000187:drug effects; D016716:PC12 Cells; D056951:Photoelectron Spectroscopy; D011092:Polyethylene Glycols / Q000737:chemistry; D058105:Polymerization / Q000528:radiation effects; D051381:Rats; D055672:Static Electricity; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D020100:Hydrogels; D037742:Nanotubes, Carbon; C437167:poly(ethylene glycol)diacrylate; D011092:Polyethylene Glycols; D003543:Cysteamine; D006046:Gold