Fabrication Of Grooved SWNT/PEDOT Composite Film For Neural Electrode

In this paper, the aligned polylactic acid (PLA) electrospun fibers were used as the sacrificed templates for the fabrication of single-walled carbon nanotubes (SWNTs)/ poly(3,4-ethylene dioxythiophene) (PEDOT) composite film with microscale grooves. Furthermore, the electrochemical behaviors, such as cyclic voltammetry (CV), electrochemical impedance, the biocompatibility and the stability of the electrodes modified with grooved SWNT/PEDOT composite film were studied.The aligned PLA fibers were firstly obtained through electrospinning with static parallel electrodes. And the morphology and diameter of fibers were influenced by the PLA concentration, solvent composition, electric filed and so on. Well aligned PLA fibers (1-2 μm) were directly deposited at the gap between the static parallel electrodes in an electrical field of 6-7 kV with the 10 wt% PLA chloroform/ethanol solution (75/25 v/v). The static parallel electrodes with a gap of 1 cm were held at a distance of 7.5 cm from the syringe needle.The SWNT film was deposited onto the electrode with aligned PLA fibers through electrophoresis. After the hydroxide and PLA fibers were dissolved, there were several hollow structures being remained in the SWNT film which can be converted into groove structures by ultrasonic bath. Field emission scanning electron microcopy (FESEM) images showed that when the deposition voltage and deposition time were controlled at 50 V and 5 min, the hollow structures can be destroyed into groove structures with diameter of 3-4 μm easily.Pulsed electro-polymerization was performed to deposit PEDOT onto SWNT to fabricate the grooved SWNT/PEDOT composite film. The electrochemical properties were also investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The electrode modified with grooved SWNT/PEDOT composite film exhibited excellent electrochemical stability and low interface impedance. Further in vitro culture of rat pheochromocytoma (PC 12) cells showed that the grooved SWNT/PEDOT composite film can not only promote neural growth and adhesion, but also guide the extension of neurite.