A single molecule immunoassay by localized surface plasmon resonance
A single molecule immunoassay by localized surface plasmon resonance
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DOI：
10.1088/0957-4484/21/25/255503
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发表时间：
2010-06-25
期刊：
影响因子：
3.5
通讯作者：
Hafner, Jason H.
中科院分区：
文献类型：
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作者：
Mayer, Kathryn M.;Hao, Feng;Hafner, Jason H.
贵金属纳米粒子由于其自由电子的共振激发（称为局域表面等离子体共振（LSPR））而在可见光和近红外频率处表现出尖锐的光谱消光峰。由于共振频率取决于纳米颗粒周围环境的折射率，因此LSPR可以成为感测纳米颗粒表面附近的分子相互作用的基础。然而，之前的研究尚未确定LSPR机制是否可以达到最终的传感极限：检测单个分子。在这里，我们展示了单分子LSPR检测通过监测抗体-抗原的非结合事件，通过散射光谱的个别金双锥。实验和有限元模拟都表明，单个抗原分子的解结合导致小的、离散的
Noble metal nanoparticles exhibit sharp spectral extinction peaks at visible and near-infrared frequencies due to the resonant excitation of their free electrons, termed localized surface plasmon resonance (LSPR). Since the resonant frequency is dependent on the refractive index of the nanoparticle surroundings, LSPR can be the basis for sensing molecular interactions near the nanoparticle surface. However, previous studies have not yet determined whether the LSPR mechanism can reach the ultimate sensing limit: the detection of individual molecules. Here we demonstrate single molecule LSPR detection by monitoring antibody-antigen unbinding events through the scattering spectra of individual gold bipyramids. Both experiments and finite element simulations indicate that the unbinding of single antigen molecules results in small, discrete