Molecularly imprinted conductive polymers for controlled trafficking of neurotransmitters at solid-liquid interfaces

We realize a molecularly imprinted polymer (MIP) which is imprinted with the retinal neurotransmitter glutamate. The films prepared by electrochemical deposition have a smooth surface with a granular morphology as observed using an atomic force microscope. Multiple reflection attenuated total reflection infrared (ATR-FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) are used to chemically confirm the imprint of a neurotransmitter in the MIP at the solid-liquid and the solid-air interface, respectively. Fluorescence spectroscopy using the dye fluorescamine is used to monitor the changes in neurotransmitter concentration in various solvents induced by application of voltage to the MIP. By controlling neurotransmitter trafficking across a solid-liquid interface with voltage, we suggest the possibility of using such a neurotransmitter imprinted MIP for chemical stimulation of retinal neurons. The current state of the art approach to restore sight in certain cases of blindness is the replacement of damaged photoreceptors by a subretinal implant consisting of light-sensitive photodiodes. Thus a future perspective of our work would be to chemically stimulate the neurons by replacing the photodiodes in the subretinal implant by the neurotransmitter imprinted polymer film.