银纳米粒子的SERS效应和SEF效应在微流控芯片光学检测中的应用

银纳米离子的SERS技术和SEF技术的信号检测灵敏度非常高，可以用在微流控芯片的定量分析中。为了提高微流控芯片光学检测技术的检测精度，提出一种在微通道中添加银纳米粒子来增强SYBR GreenⅠ拉曼和荧光信号的方法，并对该方法的原理和增强效果进行了研究。首先，利用准分子激光器在PMMA基板上直写刻蚀出宽200 μm、深68 μm的微通道，接着将制备的银前体溶液加入微通道，通过加热制备出表面增强拉曼（SERS）和表面增强荧光（SEF）基板，接下来对添加银纳米粒子前后的拉曼和荧光信号分别进行对比，进一步研究了微通道中不同浓度银纳米粒子对SYBR GREEN I的拉曼和荧光信号增强效果。添加银纳米粒子后，表面增强拉曼（SERS）实验的增强因子为3.5×10³，添加银纳米粒子的样品的荧光信号强度与不含银纳米粒子样品的荧光信号强度相比，约增加了1倍。结果表明，在微通道中检测SYBR Green I时通过增加银纳米粒子显著地增强了拉曼和荧光信号，这种方法可以用在以SYBR GreenⅠ做染料的微流控芯片检测技术中。

SERS Effect and SEF Effect of Silver Nanoparticles Applied in Optical Detection of Microfluidic Chips

SERS and SEF technology with sliver nanoparticles can achieve very high sensitivity, thus it can be used to analysis biological samples. Here, a technique was reported, which can be used to improve detection results of SYBR GreenⅠ by SERS and SEF at the same time by using silver nanoparticles in microchannels. The fundamental and enhancement effect of this method were studied. First, the excimer laser was used to write directly on the PMMA substrate to etch the microchannel with the width of 200 μm and depth of 68 μm. The prepared silver precursor solution was then added to the microchannel. The surface enhanced Raman(SERS) and surface enhanced fluorescence(SEF) substrate were prepared by heating. Next, the Raman and fluorescent signals were compared with and without adding silver nanoparticles. Besides, the effect of silver nanoparticles on the Raman and fluorescent signal enhancement of SYBR GREEN I in micro-channel was studied. The results show that the enhancement factor of the surface-enhanced Raman(SERS) experiment with silver nanoparticles is 3.5×10³. The intensity of the fluorescence signal of the samples with silver nanoparticles increases by about 1 time compared with that of the fluorescent signal without silver nanoparticles. When SYBR Green Ⅰ is detected in the microchannel, it significantly increases the Raman and fluorescent signals by adding silver nanoparticles. It can be used in microfluidic chip technology with SYBR GreenⅠ dye.