Zhang Jian, Roll David, Geddes Chris D, Lakowicz Joseph R
Center for Fluorescence Spectroscopy, University of Maryland School of Medicine, Department of Biochemistry, 725 West Lombard Street, Baltimore, Maryland 21201.
J Phys Chem B. 2004 Aug 1;108(32):12210-12214. doi: 10.1021/jp037772c. Epub 2004 Jul 21.
Tiopronin-protected silver nanoparticles ( diameter = 5 nm) were partially displaced by (2-mercapto-propionylamino) acetic acid 2,5-dioxo-pyrrolidin-1-ylesters via ligand exchange, and the succinimide-terminated silver particles were bound to amine-labeled Dextran 3000 (1 amine/per chain) or Dextran 10 000 (2.5 amine/per chain), respectively. The particle-Dextran 10 000 adducts were self-aggregated by interactions of multiple amines on Dextran and multi-functionalized ligands on the particle. The transverse plasmon band was blue shifted while the longitudinal plasmon at 575 nm increased, corresponding to the compact aggregation of particles. The particle-Dextran 3000 adducts, which were not aggregated, were coupled to Concanavalin A (Con A) to facilitate the aggregation of particles. The aggregated particles displayed an absorbance spectral change depending on the mole ratio of Con A/particle-Dextran 3000. The particle-Dextran 3000 adduct was released by a competitive complexation of glucose. This process was monitored by both the change in plasmon absorbance and wavelength, with the glucose concentration. The aggregation and dissociation of Con A/particle-Dextran complexes were also verified by TEM images.
通过配体交换，硫普罗宁保护的银纳米颗粒（直径 = 5 nm）被（2-巯基丙酰氨基）乙酸2,5-二氧代吡咯烷-1-酯部分取代，并且琥珀酰亚胺封端的银颗粒分别与胺标记的葡聚糖3000（每条链1个胺）或葡聚糖10000（每条链2.5个胺）结合。颗粒 - 葡聚糖10000加合物通过葡聚糖上的多个胺与颗粒上的多官能化配体之间的相互作用而自聚集。横向等离子体带发生蓝移，而575 nm处的纵向等离子体增加，这对应于颗粒的紧密聚集。未聚集的颗粒 - 葡聚糖3000加合物与伴刀豆球蛋白A（Con A）偶联以促进颗粒的聚集。聚集的颗粒根据Con A/颗粒 - 葡聚糖3000的摩尔比显示出吸收光谱变化。颗粒 - 葡聚糖3000加合物通过葡萄糖的竞争性络合作用而释放。通过等离子体吸收和波长随葡萄糖浓度的变化来监测这一过程。Con A/颗粒 - 葡聚糖复合物的聚集和解离也通过透射电子显微镜图像得到证实。
