Surface-grafted hybrid material consisting of gold nanoparticles and dextran exhibits mobility and reversible aggregation on a surface.
Surface-grafted hybrid material consisting of gold nanoparticles and dextran exhibits mobility and reversible aggregation on a surface.
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DOI：
10.1021/la0629431
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发表时间：
2007-03
期刊：
影响因子：
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通讯作者：
Sunmook Lee;V. Pérez-Luna
中科院分区：
文献类型：
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作者：
Sunmook Lee;V. Pérez-Luna
与线性羧化葡聚糖链连接的金纳米颗粒附着在 3-氨基丙基三乙氧基硅烷功能化的玻璃表面上。该方法在表面上提供了新颖的混合纳米结构，具有金纳米粒子的独特光学特性。附着在表面的颗粒保留了响应其环境而聚集和分解的能力。该过程提供了将金纳米粒子固定到平面基底上的替代方法。与单层金纳米颗粒相比，获得了更大的颗粒表面密度。暴露于疏水环境会改变亲水性葡聚糖链的构象，导致金纳米粒子聚集并引起吸收光谱的变化，例如等离子体吸收峰的红移和展宽。这些变化是颗粒聚集的特征，是可逆的。当基材干燥然后浸入水性环境中时，可以以可逆的方式目视观察到这些变化，并且样品的颜色从胶体金的红色变为聚集纳米颗粒的蓝紫色。当通过柔性聚合物链附着到表面时保持其移动性的表面结合纳米粒子可以将基于聚集的测定的使用扩展到固体基质。
Gold nanoparticles linked to linear carboxylated dextran chains were attached to 3-aminopropyltriethoxysilane-functionalized glass surfaces. This method provides novel hybrid nanostructures on a surface with the unique optical properties of gold nanoparticles. The particles attached to the surface retain the capability to aggregate and disaggregate in response to their environment. This procedure presents an alternative method to the immobilization of gold nanoparticles onto planar substrates. Compared to gold nanoparticle monolayers, larger particle surface densities were obtained. Exposure to hydrophobic environments changes the conformation of the hydrophilic dextran chains, causing the gold nanoparticles to aggregate and inducing changes in the absorption spectrum such as red-shifting and broadening of the plasmon absorption peaks. These changes, characteristic of particle aggregation, are reversible. When the substrates are dried and then immersed in an aqueous environment, these changes can be visually observed in a reversible fashion and the sample changes color from the red color of colloidal gold to a bluish-purple color of aggregated nanoparticles. Surface-bound nanoparticles that retain their mobility when attached to a surface by means of a flexible polymer chain could expand the use of aggregation-based assays to solid substrates.