Exploration of lignin-binding synthetic polymers with pendant hydrophobic amino acids

Abstract

Polymers bearing amino acid methyl esters with a terminus fluorescein group were synthesized through controlled radical polymerization employing a fluorescein-labeled chain transfer agent and subsequent post-polymerization modification with amino acid methyl esters. The binding properties of polymers bearing hydrophobic amino acids with milled wood lignin in water were investigated through spectroscopic analysis as screening tests and surface plasmon resonance (SPR) analysis as quantitative measurements. The polymers bearing tryptophan and phenylalanine moieties were observed to exhibit a high binding affinity. The binding parameters of polymers bearing tryptophan and phenylalanine moieties with wood lignin were determined using SPR.