title: Protein-based SERS technology monitoring the chemical reactivity on an α-synuclein-mediated two-dimensional array of gold nanoparticles.
abstract: The enhancement of weak Raman signals has been challenged to obtain high-quality signals of surface-enhanced Raman scattering (SERS). By employing the Parkinson's disease-related protein of α-synuclein, we introduce SERS-active gold nanoparticles (AuNPs) individually isolated with an ultrathin α-synuclein shell and their 2-D array into a tightly packed monolayer on a glass support, which permits a quantitative SERS measurement of phthalocyanine tetrasulfonate (PcTS), a chemical ligand of the pathological protein. Subsequently, the PcTS-bound SERS substrate was also shown to be capable of discriminating two biologically important metal ions of iron and copper by detecting copper ion to the sub-ppm level in a highly selective manner via the in situ chemical reaction of metal chelation to PcTS. The strategy of using the protein-based 2-D AuNP SERS platform, therefore, could be further developed into a custom-made protein-based biosensor system for the detection of not only specific chemical/biological ligands of the immobilized coat proteins but also their biochemical reactivities.
authors.affiliation: School of Chemical and Biological Engineering, College of Engineering, Seoul National University, Seoul 151-744, Republic of Korea.
authors.forename: Daekyun
authors.initials: D
authors.lastname: Lee
authors.forename: Young-Jun
authors.initials: YJ
authors.lastname: Choe
authors.forename: Minwoo
authors.initials: M
authors.lastname: Lee
authors.forename: Dae H
authors.initials: DH
authors.lastname: Jeong
authors.forename: Seung R
authors.initials: SR
authors.lastname: Paik
mesh_terms: D000327:Adsorption; D001672:Biocompatible Materials / Q000737:chemistry; D002384:Catalysis; D006046:Gold / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000295:instrumentation / Q000379:methods*; D013499:Surface Properties; D051844:alpha-Synuclein / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D007211:Indoles; D051844:alpha-Synuclein; C028418:tetrasulfophthalocyanine; D006046:Gold