Binary arrays of nanoparticles for nano-enhanced raman scattering molecular sensors

Abstract

A nano-enhanced Raman scattering (NERS)-active structure includes a substrate, a monolayer of nanoparticles disposed on a surface of the substrate, and a spacer material surrounding each nanoparticle in the monolayer of nanoparticles. The monolayer of nanoparticles includes a first plurality of nanoparticles and a second plurality of nanoparticles. The nanoparticles of the second plurality are interspersed among the first plurality and exhibit a plasmon frequency that differs from any plasmon frequency exhibited by the first plurality. Also described are a method for forming such a NERS-active structure and a NERS system that includes a NERS-active structure, an excitation radiation source, and a detector for detecting Raman scattered radiation.

Description

CROSS-REFERENCE TO RELATED APPLICATION [0001] The present invention is related to an invention disclosed in an application filed Mar. 17, 2005 by Kamins et al. entitled AN ORDERED ARRAY OF NANOPARTICLES FOR EFFICIENT NANOENHANCED RAMAN SCATTERING DETECTION AND METHODS OF FORMING THE SAME. FIELD OF THE INVENTION [0002] The present invention relates to nano-enhanced Raman spectroscopy (NERS). More particularly, the invention relates to NERS-active structures for use as analyte substrates in NERS, methods for forming NERS-active structures, NERS systems, and methods for performing NERS using NERS-active structures. BACKGROUND OF THE INVENTION [0003] Raman spectroscopy is a well-known technique for analyzing molecules or materials. In conventional Raman spectroscopy, high intensity monochromatic radiation provided by a radiation source, such as a laser, is directed onto an analyte (or sample) that is to be analyzed. A majority of the photons of the incident radiation are elastically sca...

AI Technical Summary

Benefits of technology

[0010] In one aspect, the present invention includes a two-dimensional array of nanoparticles usable for enhancing Raman scattered radiation in NERS. The array of nanoparticles includes a first plurality of nanoparticles and a second plurality of nanoparticles. The second plurality of nanoparticles have a size and shape substantially similar to the size and shape of the first plurality of nanoparticles. The second plurality of nanoparticles exhibits a plasmon frequency that differs from any plasmon frequency exhibited by the first plurality of nanoparticles. The nanoparticles of the second plurality of nanoparticles are interspersed among the nanoparticles of the first plurality of nanoparticles in the two-dimensional array of nanoparticles.

Problems solved by technology

As a result, powerful, costly laser sources typically are used to generate high intensity incident radiation to increase the intensity of the weak Raman scattered radiation for detection.

However, it is unknown what configurations, including size, shape and spacing, of metallic particles will enhance the intensity of Raman scattered radiation most effectively.

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