GO/PEDOT:PSS/PtNPs-modified neural microelectrode arrays for long-term dopamine monitoring in the striatum

Dopamine (DA), as an important neurotransmitter, plays a critical role in brain diseases such as epilepsy and Parkinson’s disease. Neural microelectrode arrays are key brain-machine interface devices for neural information detection and regulation, enabling real-time in situ monitoring of brain neurotransmitter levels. In this study, a neural microelectrode array designed for the striatal region of the brain was developed based on micro-electromechanical systems (MEMS) technology. By combining nanomaterials and conductive polymer modification techniques, the electrodes were composite-modified with materials such as graphene oxide (GO), poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), and platinum nanoparticles (PtNPs) to increase the specific surface area and electron transfer rate. Experimental results show that the impedance of the modified electrode (10.4 ± 0.7 kΩ) was reduced by 99.6% compared to the bare electrode. The modified microelectrode array demonstrated excellent electrochemical performance, with DA detection sensitivity reaching 11.44 pA/μM. The developed microelectrode was implanted into the striatal region of an in vivo animal brain, achieving stable DA detection for up to one month. This provides a valuable detection device for indepth research into major brain diseases.