Interaction studies of a β-cysteine functionalized polythiophene with biomolecules

Polythiophenes are an important representative class of conjugated and thermally stable polymers that can be used in alternative to inorganic semiconductors in optical and electronic devices [1]. Recently, they have been studied as biological sensors [2], thanks to the presence of the electroconducting backbone together with β-substituents able to interact with biological species. The interaction between the polymer side chain functionalities and the analyte can be of different type (hydrogen bonds, ionic interactions …) depending on the analyte, or the backbone itself can directly interact with the biomolecule through π-π stacking.In this study, a previously synthesized β-cysteine functionalized polythiophene (PTCys, Fig 1) [3] was investigated as folic acid [4] and cytochrome C (horse heart) biosensor.[1] Skotheim Ed. T., Reynolds J., Elsenbamer R., Dekker Marcel, Inc., New York, NY, USA, Handbook of conducting polymers 2nd Edition, 1998; Skotheim Ed. T., Dekker Marcel, Inc., New York, NY, USA, Handbook of conducting polymers 1986[2] Berggren, M.; Inganas, O.; Gustafsson, G.; Nature,1994, 372, 444-446[3] Cagnoli R., Lanzi M., Mucci A., Parenti F., Schenetti L., Polymer, 2005, 46(11), 3588-3596[4] Zhiyi Yao, Chun Li and Gaoquan Shi, Langmuir,2008, 24, 12829-12835