Surface Analytical Kinetic Studies of Noise-Generating Electron Transfer Processes: In Vivo Sensing Properties of Nanoengineered Organic Cardiac Pacing Electrodes in Living Heart

Published

October 12, 2021

Author(s)

H A. Chou, P DaeGynn, David J. Vanderah, M Ovadia

Abstract

Novel organic cardiac electrode candidates enhanced by self-assembled monolayers (SAMs) are examined by varying rate cyclic voltammogram and impedance spectroscopy with hexacoordinated [Fe(CN)6]-3 as the probe for their susceptibility to Faradaic current related signal distortion in perfused living rat heart. Under controlled pH, the Faradaic currents produced by the cyclic oxidation and reduction of [Fe(CN)6]-3/[Fe(CN)6]-4 complexes are found to be in direct proportion with the scan rate of the cyclic voltammogram in living, beating heart for certain SAM-modified electrodes, and not for others. The forest of the long chain thiolate and the subsequently adsorbed biological debris significantly impede the kinetics of electron transfer between the underlying metal substrate and the redox agent by erecting physical barriers for the coordination complex's ability to diffuse to the metal substrate. The asymmetrical quasi-reversible currents result from substantially lower probe diffusion coefficients from 0.83*10-7 cm2/s to 7.49*10-7 (SAM-modified electrodes in vivo) vs. the probe diffusion rate of 7.6*10-6 cm2/s (pure Au electrodes or SAM-modified electrodes in vitro).

Citation

Biosensors

Pub Type

Journals

Keywords

cyclic voltammetry, impedance spectroscopy, intracardiac signal noise, organic pacing lead, Pacemakers, protein resistance, self-assembled monolayers (SAMs

Citation

Chou, H. , DaeGynn, P. , Vanderah, D. and Ovadia, M. (2021), Surface Analytical Kinetic Studies of Noise-Generating Electron Transfer Processes: In Vivo Sensing Properties of Nanoengineered Organic Cardiac Pacing Electrodes in Living Heart, Biosensors (Accessed April 25, 2024)