Ultrathin silicon nanofilters for efficient and small scale molecular separations

描述（由申请人提供）：这项工作将研究纳米多孔硅膜（pnc-Si）在蛋白质过滤中提供革命性性能的潜力。由于新型膜材料是分子薄的（15 nm），预计将提高透析和对流过滤的效率。由于该材料由硅制成，因此制造是可扩展的，并且易于集成到微流体设备中。因此，该材料可以实现许多小规模的分析、制备和治疗装置。尽管分子薄，但多孔膜足够坚固，可以用于加压装置。目标1：我们将量化pnc-Si膜在基于扩散的分离中的功能。使用具有一系列孔隙率和孔径的膜库，我们将确定：1）模型物质和蛋白质混合物的截留尺寸;以及2）小溶质、模型颗粒和蛋白质通过pnc-Si膜的迁移率。工作将直接解决蛋白质吸附的潜在有害影响，通过测量小溶质运输的存在和不存在的高蛋白质浓度。将通过透射电子显微镜直接检查膜的生物污染证据。如果蛋白质吸附减慢了转运，则将通过用短PEG分子接枝来修饰膜，并且重新表征修饰的膜。目标二：定量表征pnc-Si膜的加压流动应用在这里，我们将检查pnc-Si膜的能力，过滤蛋白质丰富的溶液在加压微通道和离心管。在这些系统中，我们将表征PNC-Si膜的能力，从蛋白质中分离小溶质，浓缩大的物种，和fractionalcomplex混合物的大小。我们将测量体积流速，并量化蛋白质在样品中浓缩时流速的任何降低。我们将通过目标1中的直接检查和表面改性来最大限度地减少生物污垢。由于pnc-Si膜的机械性能对于加压系统中的应用至关重要，因此我们将定量确定膜在不同压力下破裂的可能性。该项目将表征一种新的硅基纳米多孔膜过滤生物液体的能力。分子薄的纳米膜有可能彻底改变过滤速率，并且是第一种可以作为模块集成到微流体系统中的过滤材料。预计这些能力将使许多新的小规模临床和诊断设备成为可能。

DESCRIPTION (provided by applicant): This work will investigate the potential of a nanoporous silicon membrane (pnc-Si) to provide revolutionary performance in protein filtration. Because the novel membrane material is molecularly thin (15 nm), it is predicted to improve the efficiency of both dialysis and convective flow filtration. Because the material is made from silicon, manufacturing is scalable and readily integrated into microfluidic devices. Thus the material may enable a host of small scale analytical, preparative, and therapeutic devices. Despite being molecularly thin, the porous membranes are strong enough to be used in pressurized devices. Aim 1: Quantitatively characterize the performance of pnc-Si membranes for diffusion- based separations We will quantify the function of pnc-Si membranes in diffusion-based separations. Using a membrane library with a range of porosities and pore sizes, we will determine: 1) rejection sizes of model species and protein mixtures; and 2) the mobility of small solutes, model particles, and proteins through pnc-Si membranes. Work will directly address the potential deleterious effects of protein adsorption by measuring small solute transport in the presence and absence of high protein concentrations. Membranes will be directly inspected for evidence of biofouling by transmission electron microscopy. If protein adsorption slows transport, membranes will be modified by grafting with short PEG molecules, and the modified membranes re-characterized. Aim 2: Quantitatively characterize pnc-Si membranes for pressurized flow applications Here we will examine the ability of pnc-Si membranes to filter protein rich solutions in pressurized minichannels and centrifuge tubes. In these systems we will characterize the ability of pnc-Si membranes to separate small solutes from proteins, concentrate large species, and fractionate complex mixtures by size. We will measure volume flow rates and quantify any reduction of flow rate when protein is concentrated in the sample. We will minimize biofouling by direct inspection and surface modification as in Aim 1. Because the mechanical properties of pnc-Si membranes are vital to applications in pressurized systems, we will quantitatively determine the likelihood of membrane bursting under different pressures. This project will characterize the ability of a new silicon-based, nanoporous membrane to filter biological fluids. The molecularly thin nanomembranes have the potential to revolutionize filtration rates and are the first filter material that can be integrated into microfluid systems as modules. These abilities are expected to enable a host of new small scale clinical and diagnostic devices.