Silver and gold glyconanoparticles for colorimetric bioassays
Silver and gold glyconanoparticles for colorimetric bioassays
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DOI：
10.1021/la060288r
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发表时间：
2006-07-18
期刊：
影响因子：
3.9
通讯作者：
Russell, David A.
中科院分区：
文献类型：
--
作者：
Schofield, Claire L.;Haines, Alan H.;Russell, David A.
与金属纳米颗粒聚集相关的颜色变化导致了基于比色的各种目标物种分析的发展。我们研究了基于银和金的纳米颗粒，以确定这两种金属是否表现出适合生物检测开发的最佳特性。这些银和金纳米粒子已经被甘露糖衍生物(2-巯乙基α-D-甘露糖苷)自组装单分子膜稳定，目的是通过利用甘露糖和刀豆蛋白A(ConA)之间众所周知的相互作用来诱导聚集。两种金属糖纳米粒的直径均为16 nm左右(用透射电子显微镜测量)。在银纳米粒子和金纳米粒子中加入ConA后，观察到了聚集现象，导致表面等离子体吸收带移动，溶液颜色发生变化，这一变化由紫外-可见分光光度法监测。甘露糖稳定的银纳米粒子在3 nm的浓度下提供了一种测定ConA的最大线性范围(在0.08-0.26微米之间)。此外，基于银纳米颗粒的生物测定体系的聚集动力学速率明显大于金纳米颗粒体系。然而，在灵敏度方面，以甘露糖稳定的金纳米颗粒为基础的检测方法的检测下限为0.04 mM Con A，而甘露糖稳定的银纳米颗粒的检测下限为0.1 mM。此外，乳糖衍生物(11-巯基-3，6，9-三氧十一烷基β-D-内酯)被用来稳定金纳米颗粒，以在添加半乳糖特异性凝集素蓖麻凝集素(RCA(120))时诱导聚集。为了检验生物测定的特异性，将乳糖稳定的金纳米颗粒与甘露糖稳定的银纳米颗粒溶液混合，建立了一种能够检测两种不同凝集素的聚集试验。当ConA或RCA(120)加入到混合糖纳米粒中时，通过单个金属纳米粒的聚集显示出对各自天然配体的选择性识别。通过对聚集物种的离心和去除，可以使用第二种糖核多糖制品系统进行进一步的生物测定。
The color changes associated with the aggregation of metal nanoparticles has led to the development of colorimetric-based assays for a variety of target species. We have examined both silver- and gold-based nanoparticles in order to establish whether either metal exhibits optimal characteristics for bioassay development. These silver and gold nanoparticles have been stabilized with a self-assembled monolayer of a mannose derivative (2-mercaptoethyl alpha-D-mannopyranoside) with the aim of inducing aggregation by exploiting the well-known interaction between mannose and the lectin Concanavalin A (Con A). Both metal glyconanoparticles were determined to be ca. 16 nm in diameter (using TEM measurements). Aggregation was observed on addition of Con A to both silver and gold nanoparticles resulting in a shift in the surface plasmon absorption band and a consequent color change of the solution, which was monitored using UV-visible spectrophotometry. Mannose-stabilized silver nanoparticles at a concentration of 3 nM provide an assay for Con A with the largest linear range (between 0.08 and 0.26 mu M). Additionally, the kinetic rate of aggregation of the silver- nanoparticle-based bioassay was significantly greater than that of the gold-nanoparticle system. However, in terms of sensitivity, the mannose-stabilized gold-nanoparticle-based assay was optimum with a limit of detection of 0.04 mu M Con A, as compared with a value of 0.1 mu M obtained for the mannose-stabilized silver nanoparticles. Additionally, a lactose derivative (11-mercapto-3,6,9-trioxaundecyl beta-D-lactoside) was used to stabilize gold nanoparticles to induce aggregation upon addition of the galactose specific lectin Ricinus communis agglutinin (RCA(120)). To examine the specificity of the bioassay, lactose-stabilized gold nanoparticles were mixed with a solution of mannose-stabilized silver nanoparticles to give an aggregation assay capable of detecting two different lectins. When either Con A or RCA(120) was added to the mixed glyconanoparticles, selective recognition of the respective natural ligand was shown by aggregation of a single metal nanoparticle. Centrifugation and removal of the aggregated species enabled further bioassay measurements using the second glyconanoparticle system.