College of Chemistry, Jilin University, Qianjin Street 2699, Changchun 130012, PR China.
Colloids Surf B Biointerfaces. 2013 Feb 1;102:165-70. doi: 10.1016/j.colsurfb.2012.08.040. Epub 2012 Sep 5.
A novel method immunosensor based on chemically functionalized Fe(3)O(4)/Ag/Au nanocomposite was developed. Fe(3)O(4)/Ag seeds were coated with Au and Fe(3)O(4)/Ag/Au nanocomposites were obtained. The nanocomposites could be obtained without violent stirring and the operation was easy and convenient. The magnetic nanocomposites can be easily immobilized on Au film of the surface plasmon resonance (SPR) biosensor with a magnetic pillar. The immobilization of Fe(3)O(4)/Ag/Au nanocomposites on the Au film leads to a large shift in resonance wavelength, which is due to the increase of the sensing membrane thickness, high dielectric constant of Ag and Au particles, and electromagnetic coupling between Fe(3)O(4)/Ag/Au nanocomposites and the Au film. The effects of Fe(3)O(4)/Ag/Au nanocomposites on the sensitivity of SPR biosensor were also investigated. As a result, the biosensor based on Au film shows a response for dog IgG in the concentration range of 1.25-20.00 μg ml(-1), whereas the SPR biosensor based on Fe(3)O(4)/Ag/Au nanocomposites shows a response for dog IgG in the concentration range of 0.15-40.00 μg ml(-1). The sensitivity of the SPR biosensor based on Fe(3)O(4)/Ag/Au nanocomposites is higher than that based on Au film.
基于化学功能化的 Fe(3)O(4)/Ag/Au 纳米复合材料的新型免疫传感器已被开发出来。Fe(3)O(4)/Ag 种子被涂覆 Au，得到 Fe(3)O(4)/Ag/Au 纳米复合材料。该纳米复合材料的获得不需要剧烈搅拌，操作简单方便。磁性纳米复合材料可以通过磁柱很容易地固定在表面等离子体共振（SPR）生物传感器的 Au 膜上。Fe(3)O(4)/Ag/Au 纳米复合材料在 Au 膜上的固定导致共振波长发生很大的偏移，这是由于传感膜厚度的增加、Ag 和 Au 颗粒的高介电常数以及 Fe(3)O(4)/Ag/Au 纳米复合材料与 Au 膜之间的电磁耦合。还研究了 Fe(3)O(4)/Ag/Au 纳米复合材料对 SPR 生物传感器灵敏度的影响。结果表明，基于 Au 膜的生物传感器在 1.25-20.00μg ml(-1)浓度范围内对犬 IgG 有响应，而基于 Fe(3)O(4)/Ag/Au 纳米复合材料的 SPR 生物传感器在 0.15-40.00μg ml(-1)浓度范围内对犬 IgG 有响应。基于 Fe(3)O(4)/Ag/Au 纳米复合材料的 SPR 生物传感器的灵敏度高于基于 Au 膜的生物传感器。
