Diagnosis, monitoring, or treatment of several neurological disorders like Alzheimer's, Parkinson’s, epilepsy, and so on, currently require the use of metallic and semiconducting materials. Regardless of their level of effectiveness, the rigidity and non-conformity of such neural electrodes and devices to the human skin pose significant constraints like frequent replacement due to scar tissue formation, or even neuronal death, especially if implanted. Conductive polymers have been widely researched for bioelectronic applications, owing to their flexibility, as well as their ability to conduct both electronically and ionically. The development of next-generation neural electrodes which could potentially form in vivo, perhaps without involving any substrate, is gaining a lot of research focus. Two water-soluble monomer precursors of conductive polymers in particular, have recently been shown to polymerise enzymatically or electrochemically, within living organisms like plants, hydra, zebra fish, and medicinal leeches. With the ultimate goal of implementing such substrate-free neural electrodes in the human nervous system, this thesis aims to study and understand the interactions of these organic conductors at the fundamental level of lipid bilayer membranes which make up the boundary of animal cells.

Interactions between the enzymatically formed polymer based on a monomer with a 2,5-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)thiophene (ETE) backbone that has been functionalised on the central thiophene with a sodium 4-ethoxy-1-butanesulphonic acid salt sidechain (ETE-S), and the phosphocholine-modified derivative (ETE-PC), with a supported lipid bilayer (SLB) system made of synthetic 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) lipids on a Au substrate, are studied in the first paper which constitutes this composite thesis. Simplification of the development of organic electrochemical transistors (OECTs) for neuromorphic applications is attempted in the second paper, by tuning their performance using mixtures of anionic ETE-S and zwitterionic ETE-PC to form the conductive channel component. An exploration of how the concentration of ETE-S affects the properties of the electrochemically polymerised films is conducted in the third paper, as a complement to the second. Finally, research done in the first paper is advanced in the fourth, by demonstrating the study of enzymatically polymerised ETE-S interacting with a native lipid membrane which is derived from F11 cell lines made up of rat embryonic dorsal root ganglion (DRG) neurons and mouse neuroblastoma, serving as a model for the mammalian nerve cell membranes.