An Jeung-Hee, El-Said Waleed Ahmed, Yea Cheol-Heon, Kim Tae-Hyung, Choi Jeong-Woo
Interdisciplinary Program and Integrated Biotechnology, Sogang University, #1 Shinsu-dong Mapo-gu, Seoul 121-742, Korea.
J Nanosci Nanotechnol. 2011 May;11(5):4424-9. doi: 10.1166/jnn.2011.3688.
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.
多巴胺是大脑中一种强效神经递质，影响多种动机行为，并在帕金森病中起主要作用。在本研究中，通过表面增强拉曼光谱（SERS）在制备的固定有纳米颗粒的玻璃表面检测多巴胺的拉曼信号。胺修饰玻璃通过胺基封端的硅烷在基底上自组装制备，随后沉积金纳米颗粒。沉积在玻璃表面的金纳米颗粒用抗多巴胺或多巴胺进行功能化。抗原多巴胺被抗体组装的金基底捕获并通过SERS检测。通过扫描电子显微镜和紫外可见吸收光谱分析固定有金纳米颗粒的玻璃基底的光学性质和形态。多巴胺的拉曼光谱在1267、1331、1158、1478、1578和1584 cm(-1)处显示宽带。光谱中最强的峰（在1267和1478 cm(-1)处）分别被确定为酚碳-氧和苯基C=C伸缩振动。在1478 cm(-1)处获得了由儿茶酚环振动与抗原多巴胺浓度构建的SERS信号工作曲线，抗多巴胺表面抗原的非优化检测限低至1 ng/ml。这些结果表明基于SERS的免疫传感器可能是检测和筛选神经递质的一种有前途的工具。
