Microelectrode Arrays Modified with Nanocomposites for Monitoring Dopamine and Spike Firings Under Deep Brain Stimulation in Rat Models of Parkinson’s Disease

Little is known about the efficacy of Deep Brain Stimulation (DBS) as an effective treatment for Parkinson’s Disease (PD) because of the lack of multichannel neural electrical and chemical detection techniques at the cellular level. In this study, a 7 mm-long and 250 μm-wide microelectrode array (MEA) was fabricated to provide real-time monitoring of dopamine (DA) concentration and neural spike firings in the Caudate Putamen (CPu) of rats with PD. Platinumn nanoparticles and reduced graphene oxide nanocomposites (Pt/rGO) were modified onto the sensitive microelectrode sites. The detection limit (50 nM) and sensitivity (8.251 pA/μM) met the specific requirements for DA detection in vivo. A single neural spike was isolated due to the high signal to noise ratio of the MEA. DBS was applied in the affected side of the globus pallidus internal (GPi) in PD rats. After DBS, the concentration of DA in the bilateral CPu increased markedly. The mean increment of the ipsilateral DA was 7.33μM (increasing from 0.54 μM...