Trinity College Dublin, Semiconductor Photonics Group, School of Physics, Dublin 2, Ireland.
J Biomed Opt. 2011 Jul;16(7):077007. doi: 10.1117/1.3600658.
Optical techniques toward the realization of sensitive and selective biosensing platforms have received considerable attention in recent times. Techniques based on interferometry, surface plasmon resonance, and waveguides have all proved popular, while spectroscopy in particular offers much potential. Raman spectroscopy is an information-rich technique in which the vibrational frequencies reveal much about the structure of a compound, but it is a weak process and offers poor sensitivity. In response to this problem, surface-enhanced Raman scattering (SERS) has received much attention, due to significant increases in sensitivity instigated by bringing the sample into contact with an enhancing substrate. Here we discuss a facile and rapid technique for the detection of pterins using SERS-active colloidal silver suspensions. Pterins are a family of biological compounds that are employed in nature in color pigmentation and as facilitators in metabolic pathways. In this work, small volumes of xanthopterin, isoxanthopterin, and 7,8-dihydrobiopterin have been examined while adsorbed to silver colloids. Limits of detection have been examined for both xanthopterin and isoxanthopterin using a 10-s exposure to a 12 mW 532 nm laser, which, while showing a trade-off between scan time and signal intensity, still provides the opportunity for the investigation of simultaneous detection of both pterins in solution.
近年来，实现敏感和选择性生物传感平台的光学技术受到了相当多的关注。基于干涉测量、表面等离子体共振和波导的技术都已被证明是受欢迎的，而光谱学尤其具有很大的潜力。拉曼光谱是一种信息量丰富的技术，其中振动频率揭示了化合物的结构很多信息，但它是一个弱过程，灵敏度较差。针对这一问题，表面增强拉曼散射（SERS）受到了广泛关注，因为通过将样品与增强衬底接触，可以显著提高灵敏度。在这里，我们讨论了一种使用 SERS 活性胶体银悬浮液检测蝶呤的简便快速技术。蝶呤是一类生物化合物，在自然界中用于色素沉着和代谢途径中的促进剂。在这项工作中，研究了吸附在银胶体上的黄蝶呤、异黄蝶呤和 7,8-二氢生物蝶呤的小体积。使用 12 mW 532 nm 激光曝光 10 秒，检测了黄蝶呤和异黄蝶呤的检测限，虽然在扫描时间和信号强度之间存在权衡，但仍为同时检测溶液中两种蝶呤提供了机会。
