Effect of conformation and drop properties on surface-enhanced Raman spectroscopy of dried biopolymer drops
Effect of conformation and drop properties on surface-enhanced Raman spectroscopy of dried biopolymer drops
复制标题
DOI：
10.1366/000370208784344370
复制
发表时间：
2008-05-01
影响因子：
3.5
通讯作者：
Morris, Michael D.
中科院分区：
文献类型：
--
作者：
Esmonde-White, Karen A.;Le Clair, Stephanie V.;Morris, Michael D.
生物流体是由小离子和大的生物聚合物如DNA、蛋白质或蛋白聚糖组成的复杂溶液。生物聚合物影响流体性质，但它们对液滴沉积的影响尚未研究。选择关节滑液中的重要成分透明质酸（HA）作为模型生物聚合物，并利用表面增强拉曼光谱（Sers）进行了研究。将纳升体积的HA溶液干燥到图案化的Sers基底上，并用近红外拉曼显微镜从干燥的透明质酸液滴收集光谱。检查了特征性透明质酸条带。毛细管粘度法测量了HA溶液的性质，并使用标度理论原理模拟了缠结行为。粘度测量被纳入模型的悬浮颗粒液滴占液滴形成的链间吸引力的影响。使用显微镜图像来评估干燥液滴的形状。相对液滴厚度估计从同心环发现在下降的边缘使用已建立的模型，薄膜的光干涉。我们发现Sers光谱不仅对聚合物构象敏感，而且对沉积类型（环形与均匀）和所得沉积的厚度敏感。这些数据表明，一种方法来阐明生物聚合物和脱水的生物流体的Sers分析的影响。
Biofluids are complex solutions consisting of small ions and large biopolymers such as DNA, proteins, or proteoglycans. Biopolymers affect fluid properties but their effect on drop deposition has not been examined. Hyaluronic acid (HA), an important component in synovial fluid, was chosen as a model biopolymer, and examined using surface-enhanced Raman spectroscopy (SERS). Nanoliter volumes of HA solutions were dried onto a patterned SERS substrate and spectra were collected from the dried hyaluronic acid drops with a near-infrared Raman microscope. Characteristic hyaluronic acid bands were examined. Capillary viscometry measured properties of HA solutions, and entanglement behavior was also modeled using scaling theory principles. Viscosity measurements were incorporated into models of suspended particle droplets to account for the effect of inter-chain attraction on droplet formation. Microscope images were used to evaluate the shape of the dried drop. Relative drop thickness was estimated from concentric rings found at drop edges using established models of light interference by thin films. We found SERS spectra were sensitive not only to polymer conformation, but also to type of deposition (ring versus uniform), and the thickness of the resulting deposition. These data suggest an approach to elucidate the effects of biopolymers and dehydrated biofluids on SERS analysis.