Desikan Ramya, Lee Ida, Thundat Thomas
Physics Department, University of Tennessee, Knoxville, 37996-1200, USA.
Ultramicroscopy. 2006 Jun-Jul;106(8-9):795-9. doi: 10.1016/j.ultramic.2005.11.012. Epub 2006 Apr 18.
Microcantilevers undergo quasi-static bending due to adsorption-induced stress when adsorption is confined to a single surface. Understanding the origin of surface stress is crucial for optimizing sensor performance. We have investigated the effect of surface morphology of gold-coated cantilevers on the adsorption characteristics of self-assembled monolayers of alkanethiols. Self-assembly of alkanethiols from liquid phase closely follows Langmuir-type kinetics up to a single monolayer assembly. Our results indicate that alkanethiol adsorption-induced surface stress is largely unaffected by surface roughness of the cantilever. Unlike prior reports that suggest surface roughness enhances adsorption-induced stress, we observe that nanometer-size roughness slightly decreases surface stress and adsorption kinetics.
当吸附作用局限于单个表面时，微悬臂梁会因吸附诱导应力而发生准静态弯曲。了解表面应力的来源对于优化传感器性能至关重要。我们研究了镀金悬臂梁的表面形态对链烷硫醇自组装单分子层吸附特性的影响。链烷硫醇从液相进行的自组装在形成单分子层组装之前严格遵循朗缪尔型动力学。我们的结果表明，链烷硫醇吸附诱导的表面应力在很大程度上不受悬臂梁表面粗糙度的影响。与之前认为表面粗糙度会增强吸附诱导应力的报道不同，我们观察到纳米级粗糙度会略微降低表面应力和吸附动力学。
