title: Surface-enhanced Raman scattering of dopamine on self-assembled gold nanoparticles.
abstract: Dopamine, a potent neurotransmitter in the brain, influences a variety of motivated behaviors and plays a major role in Parkinson's disease. In this study, the Raman signal of dopamine was detected on a fabricated nanoparticle-immobilized glass surface by surface-enhanced raman spectroscopy (SERS). Amine-modified glass was prepared by the self-assembly of amine-terminated silane on substrate, followed by the deposition of gold nanoparticles. The gold nanoparticles deposited on the glass surface were functionalized by anti-dopamine or dopamine. The antigen-dopamine was captured by antibody-assembled gold substrate and detected by SERS. The optical properties and morpology of the glass substrate with immobilized gold nanoparticles were analyzed by scanning electron microscopy and UV-VIS absorption spectroscopy. The Raman spectrum of dopamine displayed broad bands at 1267, 1331, 1158, 1478, 1578 and 1584 cm(-1). The strongest peaks in the spectra (at 1267 and 1478 cm(-1)) were identified as phenolic carbon-oxygen and phenyl C=C stretches, respectively. A working curve of the SERS signal constructed from cathecol ring vibration versus antigen-dopamine concentration was obtained at 1478 cm(-1), and the non-optimized detection limit for anti-dopamine surface antigen was as low as 1 ng/ml. These results suggest that SERS-based immunosensor can be a promising tool for the detection and screening of neurotransmitters.
authors.affiliation: Interdisciplinary Program and Integrated Biotechnology, Sogang University, #1 Shinsu-dong Mapo-gu, Seoul 121-742, Korea.
authors.forename: Jeung-Hee
authors.initials: JH
authors.lastname: An
authors.forename: Waleed Ahmed
authors.initials: WA
authors.lastname: El-Said
authors.forename: Cheol-Heon
authors.initials: CH
authors.lastname: Yea
authors.forename: Tae-Hyung
authors.initials: TH
authors.lastname: Kim
authors.forename: Jeong-Woo
authors.initials: JW
authors.lastname: Choi
mesh_terms: D004298:Dopamine / Q000032:analysis*; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles; D008855:Microscopy, Electron, Scanning; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D006046:Gold; D004298:Dopamine