Department of Applied Physics, Chalmers University of Technology, Göteborg, Sweden.
Nanotechnology. 2009 Oct 28;20(43):434015. doi: 10.1088/0957-4484/20/43/434015. Epub 2009 Oct 2.
We present a simple and robust scheme for biosensing with an ultralow limit-of-detection down to several pg cm(-2) (or several tens of attomoles cm(-2)) based on optical label-free biodetection with localized surface plasmon resonances. The scheme utilizes cost-effective optical components and comprises a white light source, a properly functionalized sensor surface enclosed in a simple fluidics chip, and a spectral analyzer. The sensor surface is produced by a bottom-up nanofabrication technique with hole mask colloidal lithography. Despite its simplicity, the method is able to reliably detect protein-protein binding events at low picomolar and femtomolar concentrations, which is exemplified by the label-free detection of the extracellular adherence protein (EAP) found on the outer surface of the bacterium Staphylococcus aureus and of prostate-specific antigen (PSA), which is believed to be a prostate cancer marker. These experiments pave the way towards an ultra-sensitive yet compact biodetection platform for point-of-care diagnostics applications.
我们提出了一种简单而稳健的生物传感方案，其检测极限低至几个 pg cm(-2)（或几十飞摩尔 cm(-2))，基于局域表面等离激元共振的无标记光学生物检测。该方案利用具有成本效益的光学元件，包括白光光源、封闭在简单流体芯片中的功能化传感器表面和光谱分析仪。传感器表面是通过底部向上的纳米制造技术与孔掩模胶体光刻法制作的。尽管该方法简单，但它能够可靠地检测低皮摩尔和飞摩尔浓度的蛋白质-蛋白质结合事件，这一点通过无标记检测金黄色葡萄球菌外表面上的细胞外黏附蛋白（EAP）和前列腺特异性抗原（PSA）得到了例证，PSA 被认为是前列腺癌的标志物。这些实验为用于即时诊断应用的超灵敏但紧凑的生物检测平台铺平了道路。
