oa Betaine feature as a powerful tool in prevention of biofouling of biosensor surfaces and membranes

Various betaine materials - single molecules or polymers - represent one of the best tools for prevention of biofouling on surfaces due to their biomimetic character and unique properties [1]. Betaines consist of internal salts in a single unit between positive quaternary ammonium and negative sulfo, carboxy or phosphate groups. This contribution highlights our progress in preparation and application of betaine materials to resist non-specific interactions on a surface of biosensors and membranes. Various betaine derivates with sulfo- [2] or carboxylbetaine groups were synthetized from lipoic acid as a natural precursor. Disulfide moiety from lipoic acid structure assists in attachment of a betaine derivative to a gold surface applied for preparation of biosensors. Biosensor devices were characterized by a set of tools including electrochemical impedance spectroscopy, FTIR, AFM, XPS, QCM, etc. Betaine derivatives introduced to the surface of various biosensors allowed their effective work in complex samples such as human plasma with a high reliability of detection and with a detection limit down to a femtomolar level for detection of specific glycoproteins. Carboxybetaine derivate provided a dual function for preparing biosensors i.e. a non biofouling surface and introduction of functional groups for covalent immobilization of sensoric biomolecules after performing a NHS/EDC coupling chemistry, as well. Moreover, formation, characterization and application of nanofibres and hydrogel from sulfo and carboxybetaine polymer as a membrane precursor will be discussed. Optimal formation of nanofibres was performed via an electrospinning process from trifluoroethanol solution. Characterization of membranes prepared was done by water sorption, FTIR, AFM and SEM techniques. Preliminarily proteins and cells attachment tests showed a dramatic decrease in adsorption and adhesion. Keywords: betaines, biomimetic, biosensor Acknowledgement: The financial support from the Slovak research and development agency APVV 0282-11 is acknowledged. The research leading to these results has received funding from the European Research Council under the European Union's Seventh Framework Programme (FP/2007-2013)/ERC Grant Agreement No. 311532 References: [1] P. Sobolciak, I. Lacik, P. Kasak Chem. Papers, 2011, 105, 918-925. [2] T. Bertok, L. Klukova, A. Sediva, P. Kasak, V. Semak, M. Micusik, M. Omastova, L. Chovanová, M. Vlcek, R. Imrich, A. Vikartovska, J. Tkac Anal. Chemistry 2013, 85, 7324-7332.