Development offunctional hydrogels for sensor applications

by Sandor Dippel

Institution: Universitt Potsdam
Year: 2017
Posted: 02/01/2018
Record ID: 2222104
Full text PDF: https://publishup.uni-potsdam.de/opus4-ubp/frontdoor/index/index/docId/39825


In this work, a sensor system basedon thermoresponsive materials is developed by utilizing a modularapproach. By synthesizing three different key monomers containingeither a carboxyl, alkene or alkyne end group connected with aspacer to the methacrylic polymerizable unit, a flexiblecopolymerization strategy has been set up with oligo ethyleneglycol methacrylates. This allows to tune the lower criticalsolution temperature (LCST) of the polymers in aqueous media. Themolar masses are variable thanks to the excurse taken inpolymerization in ionic liquids thus stretching molar masses from25 to over 1000 kDa. The systems that were shown shown to beeffective in aqueous solution could be immobilized on surfaces bycopolymerizing photo crosslinkable units. The immobilized systemswere formulated to give different layer thicknesses, swellingratios and mesh sizes depending on the demand of the couplingreaction. The coupling of detector units or model molecules isapproached via reactions of the click chemistry pool, and thereactions are evaluated on their efficiency under those aspects,too. These coupling reactions are followed by surface plasmonresonance spectroscopy (SPR) to judge efficiency. With these toolsat hand, Salmonella saccharides could be selectively detected bySPR. Influenza viruses were detected in solution by turbidimetry insolution as well as by a copolymerized solvatochromic dye to trackbinding via the changes of the polymers fluorescence by saidbinding event. This effect could also be achieved by utilizing thethermoresponsive behavior. Another demonstrator consists of thedetection system bound to a quartz surface, thus allowing the virusdetection on a solid carrier. The experiments show the greatpotential of combining the concepts of thermoresponsive materialsand click chemistry to develop technically simple sensors for largebiomolecules and viruses. Diese Arbeit befasst sich mit derEntwicklung von Sensorsystemen fr biologische Analyten wieBakterien und Viren. Die Sensoren beruhen auf thermoresponsivenPolymeren und die Entwicklung wird Schritt fr Schritt ausgehendvon der Monomersynthese dargelegt. Die Grundidee ist es alleEinzelschritte so modular wie mglich zu halten. DieKopplungseinheiten fr die spteren Erkennungsgruppen bestehen ausCarboxyl, Alken und Alkinfunktionalitten, die zuerst mit einemEthylenglycolspacer mit variabler Lnge verknpft werden und dannmit der polymerisierbaren Methylmethacrylatgruppe versehen werden.Diese koppelbaren Monomere werden mit Di- oder(Oligoethylenglycol)methacrylaten copolymerisiert. Je nachVerhltnis ist so auch die untere kritische Entmischungstemperatur(LCST) einstellbar. Mit der Erweiterung der Polymerisationstechnikum ionische Flssigkeiten als Lsemittel lassen sich Molmassen von25 bis ber 1000 kDa einstellen. Um die Polymere funktionell zuerweitern, lassen sich auch benzophenonhaltige Monomere zurVernetzung oder Immobilisierung copolymerisieren.Naphthalsureimidhaltige Monomere wiederum dienen alsAdvisors/Committee Members: Laschewsky, Andr (advisor).