孔雀绿—银纳米颗粒有望成为高效拉曼散射传感器

佚名

近年来，拉曼光谱在生物和医药领域的应用引起了人们的极大兴趣。相比于红外和荧光光谱，拉曼光谱特征峰较窄（<1nm），测试不受生物体系水环境的影响，且具有较高的化学选择性和灵敏度，这使得拉曼散射成为一种更加有效的生物检测手段。

过去，科学家们已经利用拉曼光谱实现了对单细胞中蛋白质的检测，并研究了药物在胞质体膜上的吸附，证明拉曼散射可以成功地应用于活细胞研究。最近，科研人员用孔雀绿染色剂（BG）标记的银纳米颗粒（AgNPs）作为光学探针，有效地探测了活细胞的内部环境，检测浓度可以达到微摩尔（10-6M）数量级，且对细胞毒性较小。研究发现，加入氯离子有利于增强其拉曼散射信号，使检测限降低到皮摩尔浓度（10-12M），因而这种光学探针有望成为一种高效的拉曼散射纳米传感器。

原文链接：http://pubs.acs.org/cgi-bin/abstract.cgi/jpccck/2007/111/i45/abs/jp074519u.html

Surface Enhanced Raman Scattering of Brilliant Green on Ag Nanoparticles and Applications in Living Cells as Optical Probes

Abstract:

In this article, surface enhanced Raman scattering (SERS) of different concentrations of brilliant green (BG) on Ag nanoparticles (AgNPs) has been investigated. The results indicate that only 10^-6 M BG can be detected on AgNPs while as low as 10^-12 M BG can be detected upon the activation of AgNPs by chloride ions. The additional improvement of the detection of BG mainly derives from the increase of the electromagnetic field around AgNPs and partially from the reorientation of BG on AgNPs induced by chloride ions, which was proved by the different spectra feature in the two systems. Adsorption of BG on AgNPs has also been demonstrated in applications of living cells as optical probes based on SERS, indicating that dye-AgNPs can probe the local environment in the living cells. The related cytotoxicity measurements demonstrated that BG-AgNPs produced little cytotoxicity to the cells, which shows great potential in biomedical applications of BG labeled-AgNPs for SERS nanosensors in cells as optical probes. Meanwhile, SERS spectra of BG on AgNPs in the presence chloride ions are expected to be used in living cells as more sensitive optical probes.