Surface functionalization of microelectrode array for photothermal inhibition of in vitro neural activity using Indocyanine Green (ICG)

Abstract

Over the past decades, there has been an increasing demand for neural stimulation platforms owing to their potential for applications in treating brain diseases and neuroscience research. To that end, many a neural stimulation technique has emerged, such as the ones that use chemicals, electricity and light. Amongst them, a combined use of light and photothermal materials drew a great deal of attention for their high spatiotemporal resolution and safety. In this study, the objective is to use the photothermal property of a FDA-approved NIR dye Indocyanine Green, immobilized on a MEA substrate via layer-by-layer assembly, for inhibiting neural activity. It was demonstrated that electrical firing of hippocampal neurons cultured on ICG-chip could be suppressed when exposed to near infrared stimuli. This study suggested the feasibility of using a novel material, ICG for optical neuromodulation.