The Integrated RGO/PEDOT:PSS-Modified Ultraflexible Microelectrodes Towards Long-Term Neurophysiological Signaling and Dopamine Sensitive Detection

We reported a flexible neural electrode that can simultaneously detect neural electrophysiological signals and dopamine concentration fluctuation, where the thickness is only 5 microns with bending stiffness ~4.7×10
^-12
N•m
²
that is ~3-4 orders of lower than reported [1]. The extremely thin thickness and ultralow bending stiffness cause less chemo-mechanical mismatch between the probes and the neural tissues enabling long-term stable recording. The dopamine detection electrode modified by rGO/PEDOT:PSS further improves the sensitivity of dopamine detection due to the introduction of rGO reinforcing the adsorption to dopamine, which helps to reach the sensitivity as high as 20.2 pA/μM and nanomolar detection limit with high selectivity for dopamine. The device is verified to simultaneously detect neurophysiological signals and dopamine changes in vivo. In vitro experiments verified its detection performance did not decrease significantly within two months (accelerated aging test), providing assistance for simultaneously detect dopamine and electrophysiological signals in vivo for a long time in neuroscience research. The proposed devices would be useful for neuroscience studies in small rodents, large animal and ultimately non-human primates.