Background

Proteins are large and complex molecules that are formed by amino acids. They play several important roles in our body such as structural support of cells, transport, and storage of molecules, and they can also act as a messenger. To properly understand and study the functions and the roles of the proteins in our system many technologies have been developed. However, all protein production, isolation, and purification efforts require that the proteins be separated away from other contaminates, analyzed for homogeneity, and then treated in the solution or buffer in which it is dissolved. The fact that each protein behaves differently in each of these steps can often make the task of working with isolated proteins difficult, particularly when the goal is to develop high throughput methods for their production and purification. The technology described below addresses the need for an effective and reliable nanoporous filter for protein isolation.

Description

Proteins and other functional molecules can often be synthesized in significant quantities, but their purification presents challenges. Also, many chemical/biological sensor technologies require that a small number of nanometer-sized molecules be filtered prior to being exposed to molecular recognition chemistries. Existing methods of filtering molecules by size for purification or sensing (e.g., porous microcomposites) suffer from several drawbacks, including (1) insufficiently small pore size (2) insufficiently uniform pore size, or (3) lack of mechanical stability or other deficiency in delivery mechanisms for forcing Iiquid through the pores. Thus, there is a need for low-cost filters with uniform pore size, scalable between 1-100 nm for protein screening. The smallest of these feature sizes are beyond the reach of standard lithographic processes for large areas (tens of cm2) but can be achieved with a novel fabrication process designed by LLNL scientists. The method can be used for fabricating a scalable nanoporous membrane filter to separate, sort or otherwise screen molecules, particles and proteins. Some of the key elements of the novel method are (1) an anisotropic wet chemical etch for Si (KOH, for example), (2) silicon-on-insulator wafers, and (3) controllable thermal oxidation of Si.

Ileri, et al., (2013) Phys. Chem. Chem. Phys., 15, 965-971

Advantages
  • Novel fabrication process that allows production of low-cost filters with uniform pore size that is ¬†scalable between 1 to 100 nm
Potential Applications
  • Screening of proteins to purify and characterize their folded or non-folded state
  • Sensing, purification and synthesis of other organic and inorganic molecules with characteristic dimensions between 1 and 100 nm
  • Pre-screening of toxins
  • Ultra-small pores, fabrication of which is described by this invention, can be used as a platform for sensors based on the surface-enhanced Raman effect
Development Status

LLNL has obtained a patent (US Patent 8,512,588) covering this technology (LLNL Internal Case # IL-11513)

Reference Number
470/20