High Temporal Resolution Bio-Sensing Using Nitrogen-Incorporated Nanodiamond Ultra-Microelectrode Array by Fast Scan Cyclic Voltammetry

Abstract

Microelectrodes have several benefits over macroelectrodes by virtue of their size. Their advantages include lower capacitance and uncompensated resistance loss, enhanced temporal and spatial resolution, usability in highly resistive media, increased signal to noise ratio. An array of microelectrodes can deliver these benefits along with signal amplification. Neurotransmitters, such as dopamine, undergo rapid fluctuations in concentrations occurring at a sub-second time scale. Real-time monitoring and measurement of these concentration changes, in-vivo or in-vitro, requires the use of ultra-microelectrode arrays (UMEAs). A nitrogen incorporated nanodiamond UMEA was fabricated using silicon microfabrication technology and microwave PECVD process. The array of 2500 UMEs, projects above the SiO2 insulating matrix, thus providing a 3-dimensional surface. Fast scan cyclic voltammetry at 300V/s was used to examine the temporal response and sensitivity for dopamine detection. A large negative holding potential was employed to promote DA pre-concentration in between the voltage scans.