Electrical detection of selected species

• US 20040195563A1
• Filed: 04/02/2003
• Published: 10/07/2004
• Est. Priority Date: 04/02/2003
• Status: Active Grant

• Current Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Bao, Zhenan, Yurke, Bernard
• Granted Patent: US 7,189,987 B2
• Time in Patent Office: Days
• US Class Current: 257/40
• CPC Class Codes: G01N 27/4145 specially adapted for biomolecules, e.g. gate electrode with immobilised receptors

Abstract

The present invention provides an organic field effect transistor and a method of fabricating the transistor. The transistor includes a semiconductive film comprising organic molecules. Probe molecules capable of binding to target molecules are coupled to an outer surface of the semiconductive film such that the interior of the film being substantially free of the probe molecules.

Claims

1. An organic field effect transistor for the detection of biological target molecules comprising:

a transistor channel having a semiconductive film comprising organic molecules and probe molecules coupled to an outer surface of said semiconductive film, said film having an interior substantially free of said probe molecules.

2. The transistor as recited in claim 1, wherein said organic molecules have a conjugated pi bond.

3. The transistor as recited in claim 1, wherein said organic molecules are selected from the group consisting of polythiophene and oligothiophene.

4. The transistor as recited in claim 1, wherein said semiconductive film is crystalline or polycrystalline.

5. The transistor as recited in claim 1, wherein said semiconductive film comprises a monolayer of said organic molecules, wherein one end of said organic molecules is coupled to an gate dielectric located below said semiconductive film.

6. The transistor as recited in claim 1, wherein said semiconductive film further includes a linker molecule coupled to said organic molecule at said outer surface and coupled to one of said probe molecules.

7. The transistor as recited in claim 1, wherein said transistor channel is an active channel, and wherein said probe molecules are capable of binding to target molecules and are chemical bonded to said outer surface.

8. The transistor as recited in claim 1, wherein said probe molecules are selected from the group consisting of:

single stranded DNA;

RNA;

aptamers; and

proteins, and are configured to bind to biological target molecules selected from the group consisting of;

cDNA;

mRNA; and

antibodies.

9. The transistor as recited in claim 1, wherein binding a target molecule to said probe molecule results in a change in a conductivity or mobility of said channel.

10. A method of fabricating an organic field effect transistor for the detection of biological target molecules comprising:

forming a transistor channel including;

forming a semiconductive film comprising organic molecules between a source and drain; and

coupling a probe molecule to an outer surface of said semiconductive film, said semiconductive film having an interior substantially free of said probe molecule.

11. The method as recited in claim 10, wherein said semiconductive film is polycrystalline or crystalline.

12. The method as recited in claim 10, wherein said semiconductive film is formed by depositing said organic molecules by a process selected from the group consisting of:

spin coating;

casting;

vapor deposition and printing.

13. The method as recited in claim 10, wherein said organic molecules are functionalized to improve a solubility of said organic molecule in an organic solvent prior to said forming.

14. The method as recited in claim 10, wherein said organic molecules further include a functional group capable of facilitating said coupling.

15. The method as recited in claim 10, wherein said coupling is carried out in an organic solvent selected from the groups consisting of chloroform;

toluene; and

xylene.

16. The method as recited in claim 14, wherein said probe molecules are coupled to ends of said organic molecules that are closest to said exterior surface of said film.

17. The method as recited in claim 10, wherein binding a target molecule to said probe molecule results in a change in a conductivity or mobility of said channel.

18. A biosensor system for the detection of biological target molecules comprising:

a biosensor device, including;

one or more organic field effect transistors each of said transistors including a channel comprising;

a semiconductive film comprising organic molecules; and

probe molecules capable of binding to target molecules coupled to an outer surface of said semiconductive film, said semiconductive film having an interior substantially free of said probe molecules;

a sample capable of holding said target molecules; and

an assay system configured to bring said biosensor device in contact with said sample.

19. The biosensor system as recited in claim 18, wherein said assay system comprises a micro fluidic network coupled to said transistors, said network capable of electrically isolating said channel from remaining components of said transistors.

20. The biosensor system as recited in claim 19, wherein said micro fluidic network is configured to direct multiple said sample to individual ones of said transistors of said device for parallel analysis of said samples.