A Platinum/reduced Graphene Oxide Nanocomposites Modified Nafion Coated Implantable Microelectrode Array Intent on Neural Dopamine and Electrophysiological Recordings

Abstract

A 16-channel implantable microelectrode array (MEA) was designed and fabricated by Micro-electromechanical Systems (MEMS) technology. Then the electrode sites were modified with platinum/graphene oxide nanocomposites (Pt-GO) by one-step electrochemical deposition and later handled by cyclic voltammetry reduction in phosphate buffer solution. Finally, a Nafion thin film was coated on the MEA surface. The prepared MEA sensor was intended for simultaneous detection of dopamine (DA) and electrophysiological signals. DA response performance was tested by chronoamperometry at potential of 150mV, results showed the microelectrode had a sensitivity of 17.5 pA/µM to dopamine and detection limit as low as 10nM (S/N=3). The linear range was 1 × 108 mol / L to 3.5 × 104 mol / L. Besides, it had very low response to interferences such as Ascorbic Acid, Uric Acid and 5-hydroxytryptamine. After modification, the impendences were dropped from 627.28 kΩ to 35.46 kΩon average and background noise was significantly reduced for electrical signal recording in vitro compared with bare microelectrodes. These results show the modification of Pt-rGO-Nafion on electrode surface can be a suitable way for dopamine and electrical signal detection and promising to apply in dual-mode signals measurement in vivo.