Device and method for detection and identification of biological agents

• US 7,186,567 B1
• Filed: 11/04/2005
• Issued: 03/06/2007
• Est. Priority Date: 08/29/2002
• Status: Active Grant

• Current Assignee: Leidos, Inc. (Leidos Holdings, Inc.)
• Original Assignee: Science Applications International Corporation
• Inventors: Sutherland, Richard L., Shepherd, Christina K., Brandelik, Donna M.
• Primary Examiner(s): Le; Long V.
• Assistant Examiner(s): LUM, LEON YUN BON
• Application Number:
  US11/266,189
• Time in Patent Office: 487 Days
• Field of Search: 252/582, 252/299.01, 349182-187, 349/192, 359/3, 422/50, 422/56, 422/58, 435/4, 435/6, 435 71- 72, 435/287.7, 436/518, 436528-532, 436164-165
• US Class Current: 436/532
• CPC Class Codes: G01N 21/774 the reagent being on a grating or periodic structure
• CPC Class Codes: G01N 33/54366 Apparatus specially adapted for solid-phase testing
• CPC Class Codes: G03H 2001/0264 Organic recording material
• CPC Class Codes: G03H 2250/38 Liquid crystal

Abstract

A method of sensing an environmental agent, comprising obtaining a sample from the environment and transferring the sample into the working fluid for dispensation to a detection module. The sample and working fluid mixture is filtered through a porous polymer Bragg grating. By comparing the refractive index of the grating with the mixture to the refractive index of a grating without the sample, a difference in the refractive index aids in the identification of a hazardous agent in the environment. The sensor also acts as a chemical filter by trapping specific target agents by a highly specific reaction with a conjugate molecule. Recirculation of the working fluid throughout the system provides a sensor that is “always on.”

Claims

1. A method for forming an optical sensor for sensing the presence of a target agent in a sample, the method comprising:

interfering a first coherent beam and a second coherent beam within a polymerizable polymer-dispersed liquid crystal material to form a polymerized hologram containing liquid crystals within a polymer matrix;

extracting the liquid crystals from the polymer matrix to form pores therein;

chemically activating binding sites within the pores for attaching a detector molecule thereon; and

attaching a detector molecule to the binding sites within the pores for sensing the presence of target agent in a sample.

2. The method according to claim 1 further comprising soaking the polymerized hologram in a solvent for extracting the liquid crystals from the polymer matrix.

3. The method according to claim 1 further comprising applying a vacuum to the polymerized hologram to extract the liquid crystals from the polymer matrix.

4. The method according to claim 1, wherein the polymerizable polymer dispersed liquid crystal material comprises:

(a) a polymerizable monomer;

(b) a liquid crystal;

(c) a cross-linking monomer;

(d) a coinitiator;

(e) a photoinitiator dye; and

(f) a binding site monomer.