State Key Lab of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, PR China.
Analyst. 2011 Dec 21;136(24):5261-9. doi: 10.1039/c1an15695k. Epub 2011 Oct 19.
This research investigates the origin of specific molecule-adsorption induced surface-stress for micro/nano-cantilever bio/chemical sensors. Systematic discussion is presented on the contribution from types of molecule interactions to the generated surface-stress sensing signal. With the main arguments verified by our micro-cantilever sensing experiments, the origin of the adsorption induced surface-stress is, for the first time, clearly categorized into interface vertical effects and lateral interactions, which helps to comprehensively understand the surface-stress generation and overall to optimize the sensing performance of micro-cantilever chemo-mechanical sensors. The key findings of this research are that, vertically at the molecule adsorption surface, interfacial energy change and charge redistribution are the main origins of the generated surface-stress. More importantly, intermolecular lateral interactions may make a more significant contribution to the nano-mechanical surface-stress response. Compared with other lateral interactions like van der Waals force and the electrostatic coulombic effect, intermolecular hydrogen-bond intensity and steric factor easily cause much greater disparity in surface-stress.
这项研究调查了特定分子吸附诱导微/纳悬臂生物/化学传感器表面应力的起源。文中系统地讨论了分子相互作用类型对产生的表面应力传感信号的贡献。通过我们的微悬臂梁传感实验验证了主要论点，首次明确地将吸附诱导的表面应力起源分为界面垂直效应和横向相互作用，这有助于全面理解表面应力的产生，并优化微悬臂梁化学机械传感器的传感性能。这项研究的主要发现是，在分子吸附表面的垂直方向上，界面能变化和电荷重分布是产生表面应力的主要原因。更重要的是，分子间的横向相互作用可能对纳米机械表面应力响应有更大的贡献。与范德华力和静电库仑效应等其他横向相互作用相比，分子间氢键强度和空间位阻因素很容易导致表面应力产生更大的差异。
