Electrochemical and electron microscopy data regarding improved antifouling properties of a carbon fiber microelectrode modified with a graphene oxide-silicate matrix composite

This dataset presents electrochemical and electron microscopy data to evaluate the antifouling properties of Carbon fiber microelectrodes (CFMEs).CFMEs are widely used as implantable probes for real-time in vivo neurotransmitter monitoring via fast scan cyclic voltammetry, but suffer from electrode fouling, resulting in a continuous signal loss. To prevent fouling, high switching potentials (>+1.3 V vs. Ag/AgCl) are commonly used to renew the electrode through anodic etching of the carbon surface, although this practice precludes long-term implantation and introduces background drift. Therefore, surface modifications providing enhanced fouling resistance while avoiding electrode etching protocols are vital to continual neurotransmitter monitoring. Herein, we demonstrate CFME modification using a composite containing graphene oxide and a tetramethoxysilane-derived silicate matrix (GO-SM-CFMEs). Electrochemical reduction of GO used for its deposition increased the amount of defect sites, while its subsequent oxidation increased the amount of surface oxides, thus reducing the spread of a response towards oxidation of inner-sphere dopamine from ±65% to ±25% for an unmodified CFME and GO-SM-CFME, respectively, under hemispherical diffusion conditions. An increased resistance to fouling by dopamine oxidation byproducts at a reduced switching potential of +1.0 V vs. Ag/AgCl is also reported, maintaining 83% of the initial response toward dopamine over 72 hours. Finally, GO-SM-CFMEs were also shown to be less susceptible to extracellular fouling in a mouse striatum, sustaining 21% higher responses to dopamine after one hour than an unmodified CFME. This article reports the first use of GO-SM-CFMEs and highlights the advantageous antifouling properties of GO-SM modification, allowing for reduced biofouling at CFMEs and potentially clearing the path to quantitative, real-time, in vivo neurotransmitter monitoring.