Pedot/go Carbon Fiber Microelectrodes for Dopamine Sensing

INTRODUCTION Dopamine (DA) sensing has become an important emerging technology due to the regulatory role of DA signaling in neurological diseases such as schizophrenia, addiction and Parkinson’s. However, due to its low concentration in the CNS relative to coexisting species such as ascorbic acid (AA), DA can be difficult to detect accurately. When using traditional electrodes, the recorded oxidation potentials of DA and AA are so close that their voltammetric responses often overlap, causing an interfering signal from the AA. The biologically compatible, structurally robust carbon fiber microelectrode (CFME) offers a superior alternative to the traditional electrode. CFMEs have already been extensively electrochemically characterized. They are relatively inert and resistant to fouling, while also showing good detection of catecholamines like DA. Furthermore, they are 7μm in diameter, making them less intrusive and dmazing than conventional electrodes to delicate brain tissue. The deposition of a biocompatible conducting polymer (CP), such as poly(ethylenedioxythiophene)/graphene oxide (PEDOT/GO) composite, onto the surface of the CFME further improves the electrode’s sensitivity toward DA. PEDOT has been shown to increase the separation of AA and DA peaks, thus reducing the interference from AA and increasing the precision of the DA sensing. The addition of the GO nanoparticle dopant to the PEDOT CP further increases the mechanical strength of the film as well as the sensitivity toward dopamine through ππ interactions. The sensing capacity of the CFME, used in conjunction with fast scan cyclic voltammetry (FSCV) and the PEDOT/GO composite, is optimal for use in identifying small and rapid changes is essential for the detection of DA in vivo due to its continuous fluctuation in the brain. In this study, we will characterize the DA sensing ability of the PEDOT/GO film on CFMEs in vitro to further the advancement of a tool that will help us elucidate the effect of DA in the brain in vivo.