title: Optimizing in Vitro Impedance and Physico-Chemical Properties of Neural Electrodes by Electrophoretic Deposition of Pt Nanoparticles.
abstract: Neural electrodes suffer from an undesired incline in impedance when in permanent contact with human tissue. Nanostructures, induced by electrophoretic deposition (EPD) of ligand-free laser-generated nanoparticles (NPs) on the electrodes are known to stabilize impedance in vivo. Hence, Pt surfaces were systematically EPD-coated with Pt NPs and evaluated for impedance as well as surface coverage, contact angle, electrochemically active surface area (ECSA) and surface oxidation. The aim was to establish a systematic correlation between EPD process parameters and physical surface properties. The findings clearly reveal a linear decrease in impedance with increasing surface coverage, which goes along with a proportional reduction of the contact angle and an increase in ECSA and surface oxidation. EPD process parameters, prone to yield surface coatings with low impedance, are long deposition times (40-60 min), while high colloid concentrations (>250 μg mL-1) and electric field strengths (>25 V cm-1) should be avoided due to detrimental NP assemblage effects.
authors.affiliation: Technical Chemistry I and, Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Universitätsstrasse 7, 45141, Essen, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Koenen
authors.affiliation: Technical Chemistry I and, Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Universitätsstrasse 7, 45141, Essen, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Rehbock
authors.affiliation: Department of Neurosurgery, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
authors.forename: Hans E
authors.initials: HE
authors.lastname: Heissler
authors.affiliation: Department of Neurosurgery, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
authors.forename: Svilen D
authors.initials: SD
authors.lastname: Angelov
authors.affiliation: Department of Neurosurgery, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Schwabe
authors.affiliation: Department of Neurosurgery, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
authors.forename: Joachim K
authors.initials: JK
authors.lastname: Krauss
authors.affiliation: Technical Chemistry I and, Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Universitätsstrasse 7, 45141, Essen, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Barcikowski
mesh_terms: D002627:Chemistry, Physical; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D017097:Electric Impedance; D004566:Electrodes; D004586:Electrophoresis; D053768:Metal Nanoparticles / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D020099:Coated Materials, Biocompatible; D010984:Platinum
keywords: X-ray photoelectron spectroscopy; cyclic voltammetry; electrophoretic deposition; nanoparticle coating; pulsed laser ablation in liquids