Analysis of Carbon-Based Microelectrodes for Neurochemical Sensing.

Felicia S Manciu,Kevin E Bennet,Abbas Z Kouzani,Yoonbae Oh,Kendall H Lee,Abhijeet Barath,Deidra Hodges,Jonathan Tomshine,Aaron E Rusheen,Jose Guerrero

doi:10.3390/ma12193186

Abstract

The comprehensive microscopic, spectroscopic, and in vitro voltammetric analysis presented in this work, which builds on the well-studied properties of carbon-based materials, facilitates potential ways for improvement of carbon fiber microelectrodes (CFMs) for neuroscience applications. Investigations by both, scanning electron microscopy (SEM) and confocal Raman spectroscopy, confirm a higher degree of structural ordering for the fibers exposed to carbonization temperatures. An evident correlation is also identified between the extent of structural defects observed from SEM and Raman results with the CFM electrochemical performance for dopamine detection. To improve CFM physico-chemical surface stability and increase its mechanical resistance to the induced compressive stress during anticipated in vivo tissue penetration, successful coating of the carbon fiber with boron-doped diamond (BDD) is also performed and microspectroscopically analyzed here. The absence of spectral shifts of the diamond Raman vibrational signature verifies that the growth of an unstrained BDD thin film was achieved. Although more work needs to be done to identify optimal parameter values for improved BDD deposition, this study serves as a demonstration of foundational technology for the development of more sensitive electrochemical sensors, that may have been impractical previously for clinical applications, due to limitations in either safety or performance.

Highlights

The characteristics of carbon fiber microelectrodes (CFMs) based biosensors for measuring extracellular concentrations of neurochemicals and other biological analytes, in real-time and with high accuracy, have been of continuous scientific interest for the past few decades [1,2,3,4,5,6,7,8,9]
With the objective of achieving more accurate detection and monitoring of neurotransmitters at concentrations specific to physiological levels, we present in this work a comprehensive microscopic, spectroscopic, and electrochemical analysis of CFMs fabricated from PAN-based carbon fibers (CFs)
Potential for improvements in CFMs, based on a comprehensive understanding of the structure/property relationships of the employed material still remains. This is true even for structural CFs manufactured for industrial applications, which are far more developed compared with the conductive CFs needed for in vivo electrochemical applications. in vivo implantable

Summary

Introduction

The characteristics of carbon fiber microelectrodes (CFMs) based biosensors for measuring extracellular concentrations of neurochemicals and other biological analytes, in real-time and with high accuracy, have been of continuous scientific interest for the past few decades [1,2,3,4,5,6,7,8,9]. Carbon-based materials, such as pyrolytic graphite, carbon fibers (CFs), glassy carbon (GC), pitch-based graphitic foams, nanographite ribbons, fullerenes, carbon nanotubes (CNT), and doped diamond are still considered to be the most suitable candidates because of their biocompatible, conductive, and mechanical properties [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15]. The high tensile strength-to-weight ratio, excellent thermal and chemical resistance, and high thermal and electrical conductivity of PAN-based CFs make them superior to other available candidates [17,18,19]

Methods

Results

Conclusion