ORGANIC THIN FILM TRANSISTORS AND THE USE THEREOF IN SENSING APPLICATIONS

1 . An organic thin film transistor based sensor device, the device including:

(i) a gate electrode;

(ii) a dielectric layer;

(iii) a semiconducting layer including at least one organic compound;

(iv) a source electrode;

(v) a drain electrode;

(vi) a substrate; and

(vii) an enzyme located in, or forming part of any one of (i)-(vi),

wherein the device has top gate bottom contact configuration such that the gate electrode is disposed above the dielectric layer, and the dielectric layer is disposed above the semiconducting layer.

2 . The device of claim 1 , wherein the semiconducting layer is disposed above and in between the source electrode and the drain electrode.

3 . The device of claim 1 , wherein the source electrode and the drain electrode are disposed above the substrate.

4 . The device of claim 1 , wherein the gate electrode comprises a porous matrix.

5 . The device of claim 4 , wherein the porous matrix is a sulfonated tetrafluoroethylene-based fluoropolymer-copolymer.

6 . The device of claim 5 , wherein the sulfonated tetrafluoroethylene-based fluoropolymer-copolymer is a copolymer comprising a tetrafluoroethylene backbone and perfluoroalkyl ether groups terminated with sulfonate groups.

7 . The device of claim 6 , wherein the sulfonated tetrafluoroethylene-based fluoropolymer-copolymer is ethanesulfonic acid, 2-[1-[difluoro[(1,2,2-trifluoroethenyl)oxy]methyl]-1,2,2,2-tetrafluoroethoxy]-1,1,2,2-tetrafluoro-, polymer with 1,1,2,2-tetrafluoroethene.

8 . The device of claim 1 , wherein the dielectric layer comprises poly(4-vinylphenol) or lithium perchlorate-doped poly(4-vinylpyridine).

9 . The device of claim 1 , wherein the enzyme is located in, or forms part of, the gate electrode.

10 . The device of claim 1 , wherein the enzyme is located in, or forms part of, the dielectric layer.

11 . The device of claim 1 , wherein the at least one organic compound is poly(3-hexylthiophene).

12 . The device of claim 1 , wherein the semiconducting layer has a thickness between about 5 nm and about 500 nm.

13 . The device of claim 1 , wherein the dielectric layer has a thickness between about 50 nm and 750 nm.

14 . The device according to claim 1 , wherein the enzyme is glucose oxidase.

15 . A transistor device according to claim 1 comprising: a gate electrode comprising a sulfonated tetrafluoroethylene-based fluoropolymer-copolymer and glucose oxidase, the gate electrode being disposed above, and in direct contact with, a dielectric layer, the dielectric layer being disposed above, and in direct contact with, a semiconducting layer, the semiconducting layer being disposed above and in between a source electrode and a drain electrode, and in direct contact with, the source electrode and the drain electrode, the source electrode and the drain electrode being disposed above, and in direct contact with, a substrate.

16 . A method for preparing a transistor device as defined in claim 1 comprising:

(a) depositing the source electrode and the drain electrode over the substrate;

(b) depositing the semiconducting layer comprising at least one organic compound over the source electrode and the drain electrode;

(c) depositing the dielectric layer over the semiconducting layer;

(d) depositing the gate electrode over the dielectric layer,

wherein the enzyme is introduced into the device as part of any one or more of steps a) to d).

17 . The method of claim 16 , wherein step c) comprises forming a mixture of a dielectric material and the enzyme and depositing the mixture over the semiconducting layer to form the dielectric layer.

18 . The method of claim 16 , wherein step d) comprises forming a mixture of a porous matrix and the enzyme and depositing the mixture over the dielectric layer to form the gate electrode.

19 . Use of the device of claim 1 , for sensing a compound in a sample/analyte.

20 . A method for determining a concentration or an amount of a compound in a sample/analyte comprising the compound, the method comprising the following steps:

a) providing a device as claimed in claim 1 ;

b) applying a gate voltage and a drain voltage to the device;

c) contacting the sample/analyte with the device;

d) detecting drain current; and

e) determining the concentration or the amount of the compound based on the magnitude of the drain current.