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）在蛋白质过滤方面提供革命性性能的潜力。由于这种新型膜材料分子薄（15nm），预计将提高透析和对流过滤的效率。因为这种材料是由硅制成的，所以制造是可扩展的，并且很容易集成到微流体设备中。因此，该材料可使许多小型分析、制备和治疗装置成为可能。尽管这种多孔膜分子很薄，但其强度足以用于加压设备。目的1：定量表征pnc-Si膜在扩散基分离中的性能我们将量化pnc-Si膜在扩散基分离中的功能。使用具有一系列孔隙率和孔径的膜库，我们将确定：1)模型物种和蛋白质混合物的排斥大小；2)小溶质、模型粒子和蛋白质通过pnc-Si膜的迁移性。工作将通过测量在存在和不存在高浓度蛋白质的情况下的小溶质运输，直接解决蛋白质吸附的潜在有害影响。薄膜将通过透射电子显微镜直接检查生物污染的证据。如果蛋白质吸附减缓运输，膜将通过接枝短PEG分子进行修饰，并且修饰后的膜重新表征。在这里，我们将研究pnc-Si膜在加压微通道和离心管中过滤富含蛋白质溶液的能力。在这些系统中，我们将描述pnc-Si膜从蛋白质中分离小溶质、浓缩大溶质和按尺寸分选复杂混合物的能力。我们将测量体积流速，并量化当蛋白质在样品中浓缩时流速的减少。如目标1所述，我们将通过直接检查和表面改性来减少生物污染。由于pnc-Si膜的机械性能对加压系统的应用至关重要，我们将定量确定在不同压力下膜破裂的可能性。该项目将描述一种新型硅基纳米多孔膜过滤生物流体的能力。分子薄的纳米膜有可能彻底改变过滤速度，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。这些能力有望使一系列新的小型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.