Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina 27695, USA.
ACS Nano. 2013 Jul 23;7(7):6212-8. doi: 10.1021/nn402637a. Epub 2013 Jun 12.
The interaction between light and colloidal elements can result in a wealth of interesting near-field optical patterns. By examining the optical and colloidal properties, the intensity distribution can be tailored and harnessed for three-dimensional nanolithography. Here, we examine the use of light scattering from colloidal particles to fabricate complex hollow nanostructures. In this approach, a single colloidal sphere is illuminated to create a scattering pattern, which is captured by a photoresist in close proximity. No external optical elements are required, and the colloidal elements alone provide the modulation of the optical intensity pattern. The fabricated nanostructures can be designed to have multiple shells, confined volumes, and single top openings, resembling "nano-volcanoes." The geometry of such structures is dependent on the scattered light distribution and can be accurately modeled by examining the light-particle interaction. The hollow nanostructures can be used to trap nanomaterial, and we demonstrate their ability to trap 50 nm silica nanoparticles. These well-defined surface hollow structures can be further functionalized for applications in controlled drug delivery and biotrapping. Colloidal elements with different geometries and material compositions can also be incorporated to examine other light-colloid interactions.
光与胶体元素的相互作用可以产生丰富的有趣近场光学图案。通过检查光学和胶体性质，可以调整强度分布，并用于三维纳米光刻。在这里，我们研究了利用胶体粒子的光散射来制造复杂的空心纳米结构。在这种方法中，单个胶体球被照亮以产生散射图案，该图案被近距离的光致抗蚀剂捕获。不需要外部光学元件，胶体元素本身就提供了光学强度图案的调制。所制造的纳米结构可以设计为具有多个壳、受限体积和单个顶部开口，类似于“纳米火山”。这种结构的几何形状取决于散射光的分布，并可以通过检查光-粒子相互作用来准确建模。这些空心纳米结构可用于捕获纳米材料，我们证明了它们捕获 50nm 二氧化硅纳米粒子的能力。这些定义良好的表面空心结构可以进一步官能化，用于控制药物输送和生物捕获等应用。也可以结合具有不同几何形状和材料组成的胶体元素来研究其他光-胶体相互作用。
