Materials Science and Engineering Program, Texas Materials Institute, University of Texas at Austin, Austin, TX, USA.
Walker Department of Mechanical Engineering, University of Texas at Austin, Austin, TX, USA.
Nat Nanotechnol. 2023 Oct;18(10):1213-1221. doi: 10.1038/s41565-023-01439-7. Epub 2023 Jul 27.
Owing to Brownian-motion effects, the precise manipulation of individual micro- and nanoparticles in solution is challenging. Therefore, scanning-probe-based techniques, such as atomic force microscopy, attach particles to cantilevers to enable their use as nanoprobes. Here we demonstrate a versatile electrokinetic trap that simultaneously controls the two-dimensional position with a precision of 20 nm and 0.5° in the three-dimensional orientation of an untethered nanowire, as small as 300 nm in length, under an optical microscope. The method permits the active transport of nanowires with a speed-dependent accuracy reaching 90 nm at 2.7 μm s. It also allows for their synchronous three-dimensional alignment and rotation during translocation along complex trajectories. We use the electrokinetic trap to accurately move a nanoprobe and stably position it on the surface of a single bacterial cell for sensing secreted metabolites for extended periods. The precision-controlled manipulation underpins developing nanorobotic tools for assembly, micromanipulation and biological measurements with subcellular resolution.
由于布朗运动的影响，精确地在溶液中操纵单个微纳米颗粒具有挑战性。因此，基于扫描探针的技术，如原子力显微镜，将颗粒附着在悬臂梁上，使其可以用作纳米探针。在这里，我们展示了一种通用的电动陷阱，它可以在光学显微镜下以 20nm 的精度和三维方向上 0.5°的精度同时控制无束缚纳米线的二维位置，纳米线的长度小至 300nm。该方法允许具有速度依赖性的精度的纳米线主动传输，在 2.7μm/s 的速度下达到 90nm。它还允许在沿着复杂轨迹进行易位的同时进行三维对准和旋转。我们使用电动陷阱精确地移动纳米探针，并将其稳定地定位在单个细菌细胞的表面上，以长时间稳定地检测分泌的代谢物。这种精确控制的操作为开发用于亚细胞分辨率的组装、微操作和生物测量的纳米机器人工具奠定了基础。
