Date of Award

8-9-2014

Document Type

Open Access Thesis

Department

Chemistry and Biochemistry

First Advisor

Ken D. Shimizu

Abstract

A europium-based molecularly imprinted polymer (MIP) was developed and characterized, which combined the highly luminescent properties of europium and the recognition properties of molecularly imprinted polymers. The europium-based MIPs were used as selective sensors for different types of carboxylates. The ultimate goal of this work was to develop a europium-based sensor array to differentiate carboxylates anions. The polymer was synthesized by using a europium–salen complex as the monomer and ethylene glycol dimethacrylate (EGDMA) as the crosslinker. First, a europium containing non-imprinted polymer (NIP) and a series of europium containing MIPs imprinted with acetate, benzoate and phenylacetate were synthesized by free radical polymerization. All of the polymers were able to discriminate different analytes by their different fluorescence intensity responses. The MIPs were found to have different selectivities with changes in the structure of the imprinting templates, which is a very important feature for sensor array applications. Second, the poor solubility of the monomer in the polymerization solution, which can cause an uneven distribution of the europium in the polymer, was addressed. The solubility of the europium-salen complex monomer was improved by using Eu(III) triflate as the lanthanide source instead of Eu(III) nitrate. Third, the ability to reuse the polymer sensor was tested, and both NIP and MIPs were shown to be stable and provided consistent responses after several uses. The polymers were washed with sodium nitrate aqueous solution in order to eliminate the decrease in binding efficiency after each use. Lastly, a new potential ligand, glycerol 1,3-diglycerolate diacrylate (polyalcohol), was investigated to create different coordination environment for binding analytes. The europium-polyalcohol containing polymer showed strong fluorescent intensity for the benzoate anion, which could be utilized in sensor arrays for identifying benzoate anions.

Rights

© 2014, Yang Xu

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