Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3133, United States.
Anal Chem. 2013 May 7;85(9):4560-6. doi: 10.1021/ac400192f. Epub 2013 Apr 19.
Localized surface plasmon resonance (LSPR) spectroscopy has been widely used for label-free, highly sensitive measurements of interactions at a surface. LSPR imaging (LSPRi) has the full advantages of LSPR but enables high-throughput, multiplexed measurements by simultaneously probing multiple individually addressable sensors on a single sample surface. Each spatially distinct sensor can be tailored to provide data regarding different surface functionalities or reaction environments. Previously, LSPRi has focused on single-particle sensing where the size scale is very small. Here, we create defined macroscale arrays of nanoparticles that are compatible with common patterning methods such as dip-pen nanolithography and multichannel microfluidic delivery devices. With this new LSPR sensing format, we report the first demonstration of multiplexed LSPR imaging and show that the increased throughput of our instrument enables the collection of a complete Langmuir binding curve on a single sensor surface. In addition, the multiplexed LSPR sensor is highly selective, as demonstrated by the hybridization of single-stranded DNA to complementary sequences immobilized on the sensor surface. The LSPR arrays described in this work exhibit uniform sensitivity and tailorable optical properties, making them an ideal platform for high-throughput, label-free analysis of a variety of molecular binding interactions.
局部表面等离子体共振（LSPR）光谱学已被广泛用于无标记、高灵敏度的表面相互作用测量。LSPR 成像（LSPRi）具有 LSPR 的全部优势，但通过同时探测单个样品表面上多个可单独寻址的传感器，实现了高通量、多路复用的测量。每个空间上不同的传感器都可以定制，以提供有关不同表面功能或反应环境的数据。以前，LSPRi 主要集中在单颗粒传感上，其尺寸非常小。在这里，我们创建了与常见的图案化方法（如浸笔纳米光刻和多通道微流控输送装置）兼容的定义明确的纳米粒子宏观阵列。使用这种新的 LSPR 传感格式，我们首次展示了多路复用 LSPR 成像，并表明我们仪器的高吞吐量能够在单个传感器表面上收集完整的 Langmuir 结合曲线。此外，多路复用 LSPR 传感器具有高度选择性，如固定在传感器表面上的互补序列的单链 DNA 杂交所证明的那样。本文所述的 LSPR 阵列具有均匀的灵敏度和可调节的光学特性，是各种分子结合相互作用的高通量、无标记分析的理想平台。
