title: Optical sensing of phenylalanine in urine via extraction with magnetic molecularly imprinted poly(ethylene-co-vinyl alcohol) nanoparticles.
abstract: Incorporation of superparamagnetic nanoparticles into molecularly imprinted polymers (MIPs) is useful for both bioseparations and for concentration and sensing of biomedically relevant target molecules in physiological fluids, through the application of a magnetic field. In this study, we combined the separation and concentration of a target (phenylalanine) in urine, using magnetic molecularly imprinted polymeric composite nanoparticles, with optical sensing, to improve assay sensitivity. This target is important as a catecholamine precursor, and as an important amino acid constituent of proteins. Poly(ethylene-co-vinyl alcohol)s were imprinted with target molecules, and showed a high imprinting effectiveness (target binding compared with binding to non-imprinted polymer particles.) Fluorescence spectrophotometry was used to measure binding of the target, and also binding of possible interfering compounds. These measurements suggest that functional groups on phenylalanine dominate the selectivity of the synthesized MIPs. Finally, the composite nanoparticles were used to separate and sense the target molecule in urine by Raman scattering microscopy.
authors.affiliation: Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan.
authors.forename: Chung-Yi
authors.initials: CY
authors.lastname: Hsu
authors.forename: Mei-Hwa
authors.initials: MH
authors.lastname: Lee
authors.forename: James L
authors.initials: JL
authors.lastname: Thomas
authors.forename: Ching-Ping
authors.initials: CP
authors.lastname: Shih
authors.forename: Tzu-Lin
authors.initials: TL
authors.lastname: Hung
authors.forename: Thou-Jen
authors.initials: TJ
authors.lastname: Whang
authors.forename: Hung-Yin
authors.initials: HY
authors.lastname: Lin
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D002395:Catecholamines / Q000737:chemistry; D006801:Humans; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D053761:Nanocomposites / Q000737:chemistry; D010316:Particle Size; D010649:Phenylalanine / Q000652:urine*; D011108:Polymers / Q000737:chemistry; D011145:Polyvinyls / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D002395:Catecholamines; D058185:Magnetite Nanoparticles; D011108:Polymers; D011145:Polyvinyls; C020320:ethylene-vinyl alcohol copolymer; D010649:Phenylalanine