Sensor for detection of enzyme and enzyme detection method for aerosolized bacteria in the enviromnment

• US 20040092004A1
• Filed: 10/07/2003
• Published: 05/13/2004
• Est. Priority Date: 11/07/2002
• Status: Abandoned Application

• Current Assignee: HRL Laboratories LLC (The Boeing Co.)
• Original Assignee: HRL Laboratories LLC (The Boeing Co.)
• Inventors: Stanford, Thomas B. Jr., Van Ast, Camille I.
• Application Number:
  US10/680,937
• Publication Number:
  US 20040092004A1
• Time in Patent Office: Days
• US Class Current: 435/287.1
• CPC Class Codes: C12Q 1/04 Determining presence or kind of microorganism; Use of selective media for testing antibiotics or bacteriocides; Compositions containing a chemical indicator therefor C12Q1/6897 takes precedence
• CPC Class Codes: C12Q 1/40 involving amylase

Abstract

A sensor for the detection of organisms and a method for the detection of organisms is provided, the sensor comprises a substrate; at least one pair of electrodes; a sol gel matrix comprising at least one enzyme; at least one reactant; and at least one transducer material; wherein (a) an organism expresses an enzyme on the surface of the sensor; (b) the enzyme catalyzes a reaction of the reactant of the sensor; (c) the product according to process step (b) catalytically reacted by said enzyme of the sensor; (d) the products of process step (c) modulate at least one property of the transducer material; and (e) the modulated property is measured.

Claims

1. A sensor comprising:

(a) a substrate;

(b) at least one pair of electrodes;

(c) an encapsulating matrix comprising;

(d) at least one enzyme;

(e) at least one reactant; and

(f) at least one transducer material.

2. The sensor of claim 1, wherein said substrate is selected from the group consisting of glass, ceramic, and plastic.

3. The sensor of claim 1, wherein said electrodes comprise one or more elements selected from the group consisting of gold, platinum, or silver.

4. The sensor of claim 1, wherein said electrodes are interdigitated.

5. The sensor of claim 1, wherein said sol gel matrix covers the substrate and the electrodes.

6. The sensor of claim 1, wherein said encapsulating matrix is a sol gel, said sol gel matrix comprising at least one organosilane, which may be tetrafunctional, like tetramethoxy orthosilicate, trifunctional, like methyltrimethoxysilane, octadecyltrichlorosilane, octadecyltriethoxysilane, phenyltrimethoxysilane and 1,4-bis(trimethoxysilylethyl)benzene, or difunctional, like methyldimethoxysilane, dimethyldiethoxysilane, or monofunctional, like octadecyldimethylmethoxysilane, or derivatized silanes, like 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-aminopropyltrimethoxsilyane, 4-aminobutyldimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 5-(bicycloheptenyl)triethoxysilane, dicyclohexyldimethoxysilane and 3-glycidylpropyltrimethoxysilane.

7. The sensor of claim 1, wherein said encapsulating matrix encapsulates said enzyme.

9. The sensor of claim 1, wherein said transducer material and said reactant are dispersed in said encapsulating matrix.

10. The sensor of claim 1, wherein said reactant is starch containing amylose.

11. The sensor of claim 1, wherein said transducer material is a polymer.

12. The sensor of claim 11, wherein said polymer is a water soluble polymer.

13. The sensor of claim 12, wherein said water-soluble polymer is selected from the group consisting of polyaniline, polythiophenes, polyacetylenes, polypyrroles, and combinations thereof.

8. The sensor of claim 8, wherein said enzyme may be one selected from the group consisting of tryptophanase, gelatinase, β

-lactamase, catalase, casease, citrase, decarboxylase, deoxyribonuclease, lipase, nitrate reductase, β

-galactosidase, cytochrome oxidase, phenylalanine deaminase, 1-pyrrolidonyl arylamidase, cystein desulfase, urease, L-asparaginase, glutamate dehydrogenase, organphosphorus hydrolase, acetylcholinesterase, α

-amylaseand and is preferably glucose oxidase.

14. A method for the detection of organisms by a sensor, the sensor comprising a substrate;

at least one electrode;

a sol gel matrix comprising;

at least one enzyme;

at least one reactant; and

at least one transducer material;

wherein

(a) an organism expresses an enzyme on the surface of the sensor;

(b) the enzyme causes a reaction with the reactant of the sensor;

(c) the product according to process step (b) reacts further as catalyzed by said enzyme of the sensor;

(d) the products of process step (c) modulate at least one property of the transducer material;

(e) the modulated property is measured.

15. The method according to claim 14, wherein the expressed enzyme is selected from the group consisting of tryptophanase, gelatinase, β

-lactamase, catalase, casease, citrase, decarboxylase, deoxyribonuclease, lipase, nitrate reductase, β

-galactosidase, cytochrome oxidase, phenylalanine deaminase, 1-pyrrolidonyl arylamidase, cystein desulfase, urease, L-asparaginase, glutamate dehydrogenase, organphosphorus hydrolase, acetylcholinesterase, and α

-amylase.

16. The method of claim 14, wherein said product of process step (c) is selected from the group consisting of lactic acid, carbon dioxide, hydrogen, ethanol, acetic acid, succinic acid, gluconic acid, and formic acid.

17. The method according to claim 14, wherein

(a) an organism expresses α

-amylase;

(b) α

-amylase catalyzes the hydrolysis of starch to form glucose;

(c) glucose oxidation is catalyzed by glucose oxidase to form gluconic acid and H₂O₂;

(d) gluconic acid and H₂O₂ modulate the electrical resistance of an inherently conductive polymer, or transducer material;

(e) the modulated electrical resistance of the inherently conductive polymer, or transducer material is measured with a voltage source and ohmmeter.