Method and apparatus for enhanced detection of toxic agents

• US 8,546,073 B2
• Filed: 05/17/2012
• Issued: 10/01/2013
• Est. Priority Date: 08/31/2005
• Status: Expired due to Fees

• Current Assignee: UT-Battelle LLC
• Original Assignee: UT-Battelle LLC
• Inventors: Greenbaum, Elias, Rodriguez, Miguel Jr., Wu, Jie Jayne, Qi, Hairong
• Primary Examiner(s): Ware, Debbie K
• Application Number:
  US13/474,183
• Publication Number:
  US 20120244572A1
• Time in Patent Office: 502 Days
• Field of Search: None
• US Class Current: 435/4
• CPC Class Codes: C12Q 1/025 for testing or evaluating the effect of chemical or biological compounds, e.g. drugs, cosmetics antimicrobial activity C12Q1/18

Abstract

A biosensor based detection of toxins includes enhancing a fluorescence signal by concentrating a plurality of photosynthetic organisms in a fluid into a concentrated region using biased AC electro-osmosis. A measured photosynthetic activity of the photosynthetic organisms is obtained in the concentrated region, where chemical, biological or radiological agents reduce a nominal photosynthetic activity of the photosynthetic organisms. A presence of the chemical, biological and/or radiological agents or precursors thereof, is determined in the fluid based on the measured photosynthetic activity of the concentrated plurality of photosynthetic organisms. A lab-on-a-chip system is used for the concentrating step. The presence of agents is determined from feature vectors, obtained from processing a time dependent signal using amplitude statistics and/or time-frequency analysis, relative to a control signal. A linear discriminant method including support vector machine classification (SVM) is used to identify the agents.

Claims

1. A method of biosensor-based detection of toxins, comprising the steps of:

providing for an effective fluorescent signal level by concentrating a plurality of photosynthetic organisms in a fluid to be analyzed into a concentrated region using biased AC electro-osmosis;

obtaining a measured photosynthetic activity of said photosynthetic organisms in said concentrated region, wherein chemical, biological or radiological agents reduce a nominal photosynthetic activity of said photosynthetic organisms, and

determining a presence of at least one of said chemical, biological or radiological agents, or precursors thereof, in said fluid based on said measured photosynthetic activity of said concentrated plurality of photosynthetic organisms.

2. The method of claim 1, wherein said plurality of photosynthetic organisms are naturally-occurring, free-living, indigenous organisms in said fluid.

3. The method of claim 1, wherein said photosynthetic activity comprises chlorophyll fluorescence induction.

4. The method of claim 1, wherein a lab-on-a-chip system is used for said concentrating step.

5. The method of claim 1, wherein said fluid is drawn from a source of primary-source drinking water.

6. The method of claim 5, further comprising the step of refreshing a supply of said photosynthetic organisms by drawing a fresh supply of said drinking water and repeating said method.

7. The method of claim 1, wherein said determining step further comprises the steps of:

providing at least one time-dependent control signal generated by said photosynthetic organism is said fluid;

obtaining a time-dependent biosensor signal from said biosensor in said fluid for the presence of one or more of said agents;

processing said time-dependent biosensor signal to obtain a plurality of feature vectors using at least one of amplitude statistics and a time-frequency analysis, and

determining said presence of at least one of said chemical, biological or radiological agents, or precursors thereof, from said feature vectors based on reference to said control signal.

8. The method of claim 7, wherein said time-frequency analysis comprises wavelet coefficient analysis.

9. The method of claim 7, wherein both said amplitude statistics and time-frequency analysis are used in said processing step.

10. The method of claim 7, further comprising the step of identifying which of said agents are present in said fluid.

11. The method of claim 10, wherein a linear discriminant method is used for said identifying step.

12. The method of claim 11, wherein said linear discriminant method comprises support vector machine (SVM) classification.

13. The method of claim 1, wherein a DC bias for said biased ACEO is from 1 to 10 volts.