Enhanced dopamine detection sensitivity by PEDOT/graphene oxide coating on in vivo carbon fiber electrodes

Abstract

Dopamine (DA) is a monoamine neurotransmitter responsible for regulating a variety of vital life functions. In vivo detection of DA poses a challenge due to the low concentration and high speed of physiological signaling. Fast scan cyclic voltammetry at carbon fiber microelectrodes (CFEs) is an effective method to monitor real-time in vivo DA signaling, however the sensitivity is somewhat limited. Electrodeposition of poly(3,4-ethylene dioxythiophene) (PEDOT)/graphene oxide (GO) onto the CFE surface is shown to increase the sensitivity and lower the limit of detection for DA compared to bare CFEs. Thicker PEDOT/GO coatings demonstrate higher sensitivities for DA, but display the negative drawback of slow adsorption and electron transfer kinetics. The moderate thickness resulting from 25 s electrodeposition of PEDOT/GO produces the optimal electrode, exhibiting an 880% increase in sensitivity, a 50% decrease in limit of detection and minimally altered electrode kinetics. PEDOT/GO coated electrodes rapidly and robustly detect DA, both in solution and in the rat dorsal striatum. This increase in DA sensitivity is likely due to increasing the electrode surface area with a PEDOT/GO coating and improved adsorption of DA’s oxidation product (DA-o-quinone). Increasing DA sensitivity without compromising electrode kinetics is expected to significantly improve our understanding of the DA function in vivo.

A wireless, implantable optoelectrochemical probe for optogenetic stimulation and dopamine detection

“…In the range of 0.1-10 μM, a linear relationship between the dopamine concentration and the response current can be obtained, and the detection sensitivity is determined to be ~0.06 nA/μM. For our spin coated PEDOT:PSS film, the normalized current response of dopamine by area is calculated to be 200 nA/μM/cm 2 , which is comparable to that measured by electrochemical sensors based on other materials47,48 .InFig. 3e, we further record the FSCV responses by dropping dopamine solutions in HCl, plotting the current response as a function of both time and voltage.…”

Recent Progress in the Development of Conducting Polymer‐Based Nanocomposites for Electrochemical Biosensors Applications: A Mini‐Review

“…Moreover, the sensor based PEDOT/GO films have exhibited good stability, low detection limit (0.57 μM), and acceptable sensitivity. Recently, Cui et al . have introduced electrodeposition of PEDOT/GO onto the carbon fiber microelectrode (CFE) surface to increase the sensitivity and decrease the LOD of the CFE.…”

Influence of Cathodic Pretreatment in the Electrocatalytic Properties PANI Modified Electrodes

“…Besides that, to the best of our knowledge, there are no application using the electrode modified solely with PANI for electrochemical detection of DA. The DA detection using PANI can only be achieved when others compounds as metal and carbon based nanocomposites, oxides, or complexes are combined forming composites [7]. On the other hand, electrodes modified solely with PANI have been largely applied for AA determination.…”