Ma Ying, Li Nan, Yang Cheng, Yang Xiurong
State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China.
Anal Bioanal Chem. 2005 Jun;382(4):1044-8. doi: 10.1007/s00216-005-3222-4. Epub 2005 May 20.
A sensitive method for the detection of the lectin protein concanavalin A (Con A) was developed using amino-dextran (AD)-protected gold (AD-Au) and silver nanoparticles (AD-Ag) as sensitive optical probes. The AD-Au and AD-Ag nanoparticles were synthesized by directly applying amino-dextran as a reductive and protective reagent. The size of the nanoparticles could be altered by changing the molar ratio of AD to the metal salt. The amino-dextran bound to Con A by forming a 4:1 Au-Con A complex at neutral pH, and the nanoparticles were induced to aggregate by Con A. The absorption intensity of the nanoparticles decreased linearly with as the Con A concentration was increased from 3.85 x 10(-8) to 6.15 x 10(-7) M. The Au-Con A complex was dissociated by the disaccharide isomaltose, which has a higher affinities for Con A than Au; this competitive strategy could also be used to detect similar types of saccharides.
利用氨基葡聚糖（AD）保护的金（AD-Au）和银纳米颗粒（AD-Ag）作为灵敏的光学探针，开发了一种检测凝集素伴刀豆球蛋白A（Con A）的灵敏方法。通过直接将氨基葡聚糖用作还原和保护试剂来合成AD-Au和AD-Ag纳米颗粒。通过改变AD与金属盐的摩尔比可以改变纳米颗粒的尺寸。在中性pH条件下，氨基葡聚糖通过形成4:1的金-伴刀豆球蛋白A复合物与伴刀豆球蛋白A结合，伴刀豆球蛋白A可诱导纳米颗粒聚集。随着伴刀豆球蛋白A浓度从3.85×10⁻⁸增加到6.15×10⁻⁷M，纳米颗粒的吸收强度呈线性下降。金-伴刀豆球蛋白A复合物可被二糖异麦芽糖解离，异麦芽糖对伴刀豆球蛋白A的亲和力高于金；这种竞争策略也可用于检测类似类型的糖类。
