2005 Annual Meeting
(535e) Adsorption of Dansylated Amino Acids on Molecularly Imprinted Surfaces: a Surface Plasmon Resonance Study
ABSTRACT: Surface plasmon resonance spectroscopy (SPR) was used to measure the adsorption capacities and kinetics of dansylated amino acids onto surface-confined Molecular Imprinted Polymer films (MIP-Fs) and the corresponding Non-Imprinted Polymer control films (NIP-Fs). The surface-confined polymer films were grafted from flat gold surfaces using Atom Transfer Radical Polymerization (ATRP). This approach allows nanothin films to be grown with molecular level control of structure, thereby ensuring that the amino acids see a uniform surface during adsorption. N,N'-didansyl-L-cystine (DDC) and didansyl-L-lysine (DDL) were used as the template molecules to form the MIPs. Dansylated amino acids were chosen to allow eventual comparison of results between SPR and fluorometry. Adsorption kinetics were analyzed using single site and dual-site Langmuir adsorption models. In all SPR measurements, MIP films exhibited higher binding capacities than NIP films. Selectivity studies showed that the MIPs display cross-reactivity between DDC and DDL; nevertheless, MIPs prepared against one template showed selectivity for that template. Solution pH and polymer layer thickness were studied as independent parameters to determine their impacts on amino acid adsorption.
KEY WORDS: ATRP, binding kinetics, graft polymerization, molecular imprinting, SPR.