Shu Wenmiao, Laue Ernest D, Seshia Ashwin A
The Nanoscience Centre, University of Cambridge, 11 J.J. Thomson Avenue, Cambridge CB3 0FF, UK.
Biosens Bioelectron. 2007 Apr 15;22(9-10):2003-9. doi: 10.1016/j.bios.2006.08.047. Epub 2006 Oct 12.
We report the investigation of biotin-streptavidin binding interactions using microcantilever sensors. A symmetric cantilever construction is employed to minimize the effects of thermal drift and the control of surface chemistry on the backside of the cantilever is demonstrated to reduce the effects of non-specific binding interactions on the cantilever. Three structurally different biotin modified cantilever surfaces are used as a model system to study the binding interaction with streptavidin. The cantilever response to the binding of streptavidin on these biotin sensing monolayers is compared. The lowest detection limit of streptavidin using biotin-HPDP is found to be between 1 and 10nM limited by the optical measurement setup. Surface characterization using quartz crystal microbalance (QCM) and high-resolution atomic force microscope (AFM) is used to benchmark the cantilever sensor response. In addition, the QCM and AFM studies reveal that the surface density of bound streptavidin on biotin modified surfaces was low, thereby implying that effects other than steric hindrance are responsible for defining cantilever response.
我们报告了使用微悬臂梁传感器对生物素-链霉亲和素结合相互作用的研究。采用对称悬臂梁结构以最小化热漂移的影响，并证明对悬臂梁背面的表面化学进行控制可减少非特异性结合相互作用对悬臂梁的影响。使用三种结构不同的生物素修饰悬臂梁表面作为模型系统来研究与链霉亲和素的结合相互作用。比较了悬臂梁对链霉亲和素在这些生物素传感单分子层上结合的响应。受光学测量装置限制，使用生物素-对二硫代吡啶（biotin-HPDP）时链霉亲和素的最低检测限在1至10 nM之间。使用石英晶体微天平（QCM）和高分辨率原子力显微镜（AFM）进行表面表征，以对悬臂梁传感器的响应进行基准测试。此外，QCM和AFM研究表明，生物素修饰表面上结合的链霉亲和素的表面密度较低，从而意味着除空间位阻外的其他效应是决定悬臂梁响应的原因。
