Porous microstructure multi layer spectroscopy and biosensing

Abstract

A preferred embodiment biosensor is a multi-layer micro-porous thin film structure. Pores in a top layer of the micro-porous thin film structure are sized to accept a first molecule of interest. Pores in a second layer of the micro-porous thin film structure are smaller than the pores in the top layer and are sized to accept a second molecule of interest that is smaller than the first molecule of interest. The pores in the second layer are too small to accept the first molecule of interest. The pores in the top layer and the pores in the second layer are sized and arranged such that light reflected from the multi-layer micro-porous thin film structure produces multiple superimposed interference patterns that can be resolved. In preferred embodiments, the multi-layer micro-porous thin film structure is a porous silicon thin film multi-layer structure formed on a silicon substrate, such as a silicon wafer. Specific and nonspecific binding can be detected with biosensors of the invention. The position of peaks in the Fourier transform of the reflection spectrum and the shift in peak amplitudes can be used to determine the presence and quantity of targeted biological molecules of interest.

Description

REFERENCE TO RELATED APPLICATION AND PRIORITY CLAIM [0001] This application claims priority under 35 U.S.C. §119 to provisional application Ser. No. 60 / 660,421 filed on Mar. 10, 2005 and entitled Porous Microstructure Multi Layer Spectroscopy and Biosensing.STATEMENT OF GOVERNMENT INTEREST [0002] The invention was made with Government assistance from the National Cancer Institute of the National Institutes of Health Contract No. N01-C0-37117 and the Air Force Office of Scientific Research Grant No. F49620-02-1-0288. The Government has certain rights in the invention.FIELD OF THE INVENTION [0003] A field of the invention is biosensing. Particular example applications for porous microstructures of the invention include label-free biomolecule sensing. BACKGROUND [0004] Porous microstructures have been demonstrated to produce characteristic spectral interference patterns. Porous silicon has been used to produce characteristic spectral interference patterns, and other semiconductors and ...

AI Technical Summary

Benefits of technology

[0009] A preferred embodiment biosensor is a multi-layer micro-porous thin film structure. Pores in a top layer of the micro-porous thin film structure are sized to accept a first molecule of interest. Pores in a second layer of the micro-porous thin film structure are smaller than the pores in the top layer and are sized to accept a second molecule of interest that is smaller than the first molecule of interest. The pores in the second layer are too small to accept the first molecule of interest. The pores in the top layer and the pores in the second layer are sized and arranged such that light reflected from the multi-layer micro-porous thin film structure produces multiple superimposed interference patterns that can be resolved. In preferred embodiments, the multi-layer micro-porous thin film structure is a porous silicon thin film multi-layer structure formed on a silicon substrate, such as a silicon wafer. Specific and nonspecific binding can be detected with biosensors of the invention. A shift in the position of peaks in the Fourier transform of the reflection spectrum and / or a shift in the intensity of the peak amplitudes can be used to determine the presence and quantity of targeted biological molecules of interest.

Problems solved by technology

The non-interference based sensing methods have difficulty in noisy environments, require more sensitive equipment to achieve comparable sensitivity, and fail to account for common measurement conditions, e.g., signal drift due to thermal fluctuation, changes in sample composition, or degradation of the sample matrix.

A disadvantage of this approach is that determination of protein size requires optical sampling over a relatively large area of the porous Si film.

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