Materials Research and Education Center, Auburn University , Auburn, Alabama 36849, United States.
Department of Mechanical Engineering, Tsinghua University , Beijing, 100084, People's Republic of China.
Nano Lett. 2017 Apr 12;17(4):2374-2380. doi: 10.1021/acs.nanolett.6b05313. Epub 2017 Mar 17.
Label-free, nanoparticle-based plasmonic optical biosensing, combined with device miniaturization and microarray integration, has emerged as a promising approach for rapid, multiplexed biomolecular analysis. However, limited sensitivity prevents the wide use of such integrated label-free nanoplasmonic biosensors in clinical and life science applications where low-abundance biomolecule detection is needed. Here, we present a nanoplasmofluidic device integrated with microelectrodes for rapid, label-free analysis of a low-abundance cell signaling protein, detected by AC electroosmosis-enhanced localized surface plasmon resonance (ACE-LSPR) biofunctional nanoparticle imaging. The ACE-LSPR device is constructed using both bottom-up and top-down sensor fabrication methods, allowing the seamless integration of antibody-conjugated gold nanorod (AuNR) biosensor arrays with microelectrodes on the same microfluidic platform. Applying an AC voltage to microelectrodes while scanning the scattering light intensity variation of the AuNR biosensors results in significantly enhanced biosensing performance. The AC electroosmosis (ACEO) based enhancement of the biosensor performance enables rapid (5-15 min) quantification of IL-1β, a pro-inflammatory cytokine biomarker, with a sensitivity down to 158.5 fg/mL (9.1 fM) for spiked samples in PBS and 1 pg/mL (58 fM) for diluted human serum. Together with the optimized detection sensitivity and speed, our study presents the first critical step toward the application of nanoplasmonic biosensing technology to immune status monitoring guided by low-abundance cytokine measurement.
无标记、基于纳米颗粒的等离子体光学生物传感，结合器件小型化和微阵列集成，已成为一种快速、多重生物分子分析的有前途的方法。然而，由于灵敏度有限，这种集成的无标记纳米等离子体生物传感器在需要检测低丰度生物分子的临床和生命科学应用中还无法广泛使用。在这里，我们提出了一种与微电极集成的纳米等离子体流控装置，用于快速、无标记地分析低丰度细胞信号蛋白，通过交流电泳增强的局域表面等离子体共振（ACE-LSPR）生物功能纳米粒子成像进行检测。该 ACE-LSPR 装置采用自下而上和自上而下的传感器制造方法构建，允许将抗体偶联的金纳米棒（AuNR）生物传感器阵列与微电极无缝集成在同一个微流控平台上。在扫描 AuNR 生物传感器的散射光强度变化的同时施加交流电压，可显著提高生物传感性能。基于交流电泳（ACEO）的生物传感器性能增强，可快速（5-15 分钟）定量 PBS 中 IL-1β（一种促炎细胞因子生物标志物），其灵敏度可低至 158.5 fg/mL（9.1 fM）（用于 PBS 中的加标样品）和 1 pg/mL（58 fM）（用于稀释的人血清）。结合优化的检测灵敏度和速度，我们的研究代表了将纳米等离子体生物传感技术应用于基于低丰度细胞因子测量的免疫状态监测的关键的第一步。
