局域表面等离子体光学传感器由于其体积小、灵敏度高、免标记等特点成为目前传感器研究热点之一。然而由于银纳米结构的生物兼容性以及氧化问题,成为该传感器发展的瓶颈。提出了利用金/银混合的金属纳米结构克服上述困难,并从有限时域差分数值计算方法入手,设计了银层50 nm,金层5 nm的六边形分布三角形复合传感结构,并利用纳米球自组装技术实现了该类型传感器。同时,与生物分子蛋白A的结合实验结果表明,该传感器在生物分子溶液浓度213.85 nM的条件下仍然具有较高的灵敏度。

It is well known that the localized surface plasmon resonance(LSPR) biosensor based on Ag nanotriangles is widely used due to its high sensitivity. However, such biosensor can only be stored for a short time because the Ag nanostructures are chemically instable and biologically incompatible. In this paper, the sensitivity of composite gold-silver LSPR sensors for stable performance is studied by using finite difference time domain (FDTD). Its shown that the optimal configuration for such composite LSPR sensor should be gold(5 nm)-silver(40 nm) for comparable sensitivity to traditional Ag LSPR sensor. With the detection of target molecule (Protein A), and such sensor can response under concentration of 213.85 nM.