McKendry Rachel, Zhang Jiayun, Arntz Youri, Strunz Torsten, Hegner Martin, Lang Hans Peter, Baller Marko K, Certa Ulrich, Meyer Ernst, Güntherodt Hans-Joachim, Gerber Christoph
IBM Research, Zurich Research Laboratory, 8803 Rüschlikon, Switzerland.
Proc Natl Acad Sci U S A. 2002 Jul 23;99(15):9783-8. doi: 10.1073/pnas.152330199. Epub 2002 Jul 15.
We report a microarray of cantilevers to detect multiple unlabeled biomolecules simultaneously at nanomolar concentrations within minutes. Ligand-receptor binding interactions such as DNA hybridization or protein recognition occurring on microfabricated silicon cantilevers generate nanomechanical bending, which is detected optically in situ. Differential measurements including reference cantilevers on an array of eight sensors can sequence-specifically detect unlabeled DNA targets in 80-fold excess of nonmatching DNA as a background and discriminate 3' and 5' overhangs. Our experiments suggest that the nanomechanical motion originates from predominantly steric hindrance effects and depends on the concentration of DNA molecules in solution. We show that cantilever arrays can be used to investigate the thermodynamics of biomolecular interactions mechanically, and we have found that the specificity of the reaction on a cantilever is consistent with solution data. Hence cantilever arrays permit multiple binding assays in parallel and can detect femtomoles of DNA on the cantilever at a DNA concentration in solution of 75 nM.
我们报道了一种悬臂式微阵列，可在数分钟内同时检测纳摩尔浓度下的多种未标记生物分子。在微加工硅悬臂上发生的配体-受体结合相互作用，如DNA杂交或蛋白质识别，会产生纳米机械弯曲，可通过原位光学检测。在由八个传感器组成的阵列上，包括参考悬臂的差分测量，能够以序列特异性方式检测未标记的DNA靶标，背景中存在80倍过量的不匹配DNA，并且能够区分3'和5'突出端。我们的实验表明，纳米机械运动主要源于空间位阻效应，并取决于溶液中DNA分子的浓度。我们证明悬臂阵列可用于通过机械方式研究生物分子相互作用的热力学，并且我们发现悬臂上反应的特异性与溶液数据一致。因此，悬臂阵列允许并行进行多种结合测定，并且在溶液中DNA浓度为75 nM时，能够检测到悬臂上飞摩尔级的DNA。
