Mater Sci Eng C Mater Biol Appl. 2012 Aug 1;32(6):1437-42. doi: 10.1016/j.msec.2012.04.023. Epub 2012 Apr 24.
The specific sensitivity of surface plasmon resonance to changes in the local environment of nanoparticles allows their use as platforms to probe chemical and biochemical binding events on their surfaces without any labeling [1-4]. In this paper, we perform a comparative study of gold and silver nanoparticle based biosensors, prepared within the same conditions, in order to determine which metal seems the best for biological sensing. The prototypical biocytin-avidin interaction is used to study gradual changes over time and with avidin concentration in the absorption spectra bands of biocytinylated 10 nm silver and gold nanospheres. First, the Ag nanoparticles plasmon resonance absorbance signal is about 10 times larger than the Au one. Secondly, for an equivalent concentration of avidin, the optical property modifications are more pronounced for silver nanoparticles than for gold ones of the same geometry. These observations attest the superiority of Ag on Au nanoparticles when optical considerations are only taken into account. Finally, with both biosensors, the specificity of the interaction, checked by replacing avidin with bovine serum albumin, is relatively poor and needs to be improved.
表面等离子体共振对纳米粒子局部环境变化的特殊敏感性，使其可以用作平台，无需任何标记[1-4]，来探测其表面的化学和生化结合事件。在本文中，我们对基于金和银纳米粒子的生物传感器进行了比较研究，这些传感器是在相同条件下制备的，以确定哪种金属最适合用于生物传感。生物胞嘧啶-亲和素相互作用的原型用于研究在时间和亲和素浓度上的逐渐变化，以及生物胞嘧啶化的 10nm 银和金纳米球的吸收光谱带。首先，Ag 纳米粒子等离子体共振吸收信号大约是 Au 纳米粒子的 10 倍。其次，对于相同几何形状的相同浓度的亲和素，银纳米粒子的光学性质变化比金纳米粒子更为明显。这些观察结果证明了在仅考虑光学因素的情况下，Ag 纳米粒子优于 Au 纳米粒子。最后，对于这两种生物传感器，通过用牛血清白蛋白代替亲和素来检查相互作用的特异性，其特异性相对较差，需要改进。
