Karlsson Anders, Karlsson Mattias, Karlsson Roger, Sott Kristin, Lundqvist Anders, Tokarz Michal, Orwar Owe
Department of Chemistry, Göteborg University, SE-412 96 Göteborg, Sweden.
Anal Chem. 2003 Jun 1;75(11):2529-37. doi: 10.1021/ac0340206.
We explore possibilities to construct nanoscale analytical devices based on lipid membrane technology. As a step toward this goal, we present nanotube-vesicle networks with fluidic control, where the nanotube segments reside at, or very close (<2 microm) to optically transparent surfaces. These nanofluidic systems allow controlled transport as well as LIF detection of single nanoparticles. In the weak-adhesion regime, immobilized vesicles can be approximated as perfect spheres with nanotubes attached at half the height of the vesicle in the axial (z) dimension. In the strong-adhesion regime (relative contact area, Sr* approximately 0.3), nanotubes can be adsorbed to the surface with a distance to the interior of the nanotubes defined by the membrane thickness of approximately 5 nm. Strong surface adsorption restricts nanotube self-organization, enabling networks of nanotubes with arbitrary geometries. We demonstrate LIF detection of single nanoparticles (30-nm-diameter fluorescent beads) inside single nanotubes. Transport of nanoparticles was induced by a surface tension differential applied across nanotubes using a hydrodynamic injection protocol. Controlled transport in nanotubes together with LIF detection enables construction of nanoscale fluidic devices with potential to operate with single molecules. This opens up possibilities to construct analytical platforms with characteristic length scales and volume orders of magnitudes smaller than employed in traditional microfluidic devices.
我们探索基于脂质膜技术构建纳米级分析设备的可能性。作为朝着这个目标迈出的一步，我们展示了具有流体控制的纳米管-囊泡网络，其中纳米管段位于光学透明表面或非常靠近该表面（<2微米）。这些纳米流体系统允许对单个纳米颗粒进行可控传输以及激光诱导荧光检测。在弱粘附状态下，固定的囊泡可以近似为完美的球体，纳米管附着在囊泡轴向（z）维度高度的一半处。在强粘附状态下（相对接触面积，Sr*约为0.3），纳米管可以吸附到表面，纳米管内部与表面的距离由约5纳米的膜厚度定义。强烈的表面吸附限制了纳米管的自组织，从而形成具有任意几何形状的纳米管网。我们展示了对单个纳米管内单个纳米颗粒（直径30纳米的荧光珠）的激光诱导荧光检测。使用流体动力注射方案，通过在纳米管上施加表面张力差来诱导纳米颗粒的传输。纳米管中的可控传输以及激光诱导荧光检测使得构建具有单分子操作潜力的纳米级流体设备成为可能。这为构建特征长度尺度和体积比传统微流体设备小几个数量级的分析平台开辟了可能性。
