NU 2013-221

Inventors

Hao F. Zhang*

Cheng Sun

Ben E Urban

Short Description

An optical microscopy technique that uses spontaneous Raman scattering to characterize materials and biological tissues beyond the optical diffraction limit

Background

Optical microscopes are limited in their ability to resolve individual features that are below a certain size. Great efforts have been made to overcome this challenge using different physical processes. Techniques such as near-field scanning optical microscopy (NSOM), stimulated emission depletion microscopy (STED), photoactivated localization microscopy (PALM) and stochastic optical reconstruction microscopy (STORM) have been developed and are capable of resolving objects beyond the diffraction limit. However, many of these techniques are limited in their application as they lack the ability to determine material composition and, for biological applications, rely on cytotoxic fluorescent dyes.

Abstract

Raman-STORM is a new microscopy technique developed by Northwestern scientists that overcomes the limitations of current optical microscopy techniques in a cost- and time-efficient manner. Using stochastic Raman scattering, this technique can both determine material composition and capture images beyond the diffraction limit without the time constraints of other fluorescent counterparts. The ability to determine structural information beyond the diffraction limit has widespread applications in material and biological analysis. In molecular imaging, Raman-STORM can be used to resolve features that are below the diffraction limit without the cytotoxic effect of molecular contrast agents. In the analysis of materials, characterizing semiconductor purity can have significant implications in improved semiconductor properties and longer lifetimes. In contrast to the current gold standard, electron microscopy, Raman-STORM would allow for high-resolution optical imaging and material characterization that is faster and less expensive. The inventors also contend that the resolution of Raman-STORM can rival the resolution of electron microscopes based on initial theoretical calculations. Furthermore, Raman-STORM can be adapted to analyze a larger range of sample types than electron microscopy, offering greater versatility of analysis to fabricators who must create consistently high-quality materials.

Applications

• Quality Management of Semiconductors and Other Materials: Surface characterization, purity, defects
• Molecular imaging of biological samples

Advantages

• Reagentless
• Lower cell toxicity
• Faster analysis
• Reduced cost
• Samples can be imaged in vivo as the technique is not affected by water or other media.

IP Status

US and PCT patent applications have been filed.