Shekhawat Gajendra, Tark Soo-Hyun, Dravid Vinayak P
International Institute for Nanotechnology, Northwestern University, Evanston, IL 60208, USA.
Science. 2006 Mar 17;311(5767):1592-5. doi: 10.1126/science.1122588. Epub 2006 Feb 2.
A promising approach for detecting biomolecules follows their binding to immobilized probe molecules on microfabricated cantilevers; binding causes surface stresses that bend the cantilever. We measured this deflection, which is on the order of tens of nanometers, by embedding a metal-oxide semiconductor field-effect transistor (MOSFET) into the base of the cantilever and recording decreases in drain current with deflections as small as 5 nanometers. The gate region of the MOSFET responds to surface stresses and thus is embedded in silicon nitride so as to avoid direct contact with the sample solution. This approach, which offers low noise, high sensitivity, and direct readout, was used to detect specific binding events with biotin and antibodies.
一种检测生物分子的很有前景的方法是，让生物分子与微加工悬臂梁上固定的探针分子结合；结合会产生使悬臂梁弯曲的表面应力。我们通过将金属氧化物半导体场效应晶体管（MOSFET）嵌入悬臂梁的基部，并记录漏极电流随小至5纳米的挠度的减小情况，来测量这种在几十纳米量级的挠度。MOSFET的栅极区域对表面应力有响应，因此被嵌入氮化硅中，以避免与样品溶液直接接触。这种具有低噪声、高灵敏度和直接读出功能的方法，被用于检测生物素和抗体的特异性结合事件。
