Electronic sensor for nitric oxide
Disclosed is a semiconductor device ( 1 ) for determining NO concentrations in fluids such as exhaled breath. The device ( 1 ) typically comprises a pair of electrodes ( 18 ) separated from each other to define a channel region ( 16 ) in an organic semiconductor ( 14 ), a gate structure ( 10 ) for controlling said channel region, and a receptor layer ( 22 ) at least partially overlapping said channel region, said receptor layer comprising a porphine or phtalocyanine coordination complex including a group III-XII transition metal ion or a lead (Pb) ion for complexing NO. Such a semiconductor device is capable of sensing NO concentrations in the ppb range.
1. A semiconductor device comprising a pair of electrodes separated from each other to define a channel region in an organic semiconductor layer, a gate structure for controlling said channel region, and a receptor layer at least partially overlapping said channel region, said receptor layer comprising a nitric oxide coordination complex selected from Formula I or Formula II:
wherein M is Pb or a transition metal ion selected from group 3 to group 12 transition metals, wherein R is an unsubstituted or substituted arylene or heteroarylene functional group and wherein X is a nitride or a halide ion.
2. The semiconductor device of claim 1 , wherein the transition metal ion is selected from Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Pb and Zn.
3. The semiconductor device of claim 2 , wherein the transition metal ion is a Fe ion.
4. The semiconductor device of claim 3 , wherein the nitric oxide coordination complex is the compound of Formula III:
wherein R′ is hydrogen or an alkyl substituent, and wherein X is a halide or nitrate ion.
5. A semiconductor device, comprising:
a pair of electrodes separated from each other to define a channel region in an organic semiconductor layer;
a gate structure for controlling said channel region, and a receptor layer at least partially overlapping said channel region;
wherein the gate structure and the receptor layer are located on opposite sides of the channel region and the receptor layer comprises a nitric oxide coordination complex selected from Formula I or Formula II:
wherein M is Pb or a transition metal ion selected from group 3 to group 12 transition metals, wherein R is an unsubstituted or substituted arylene or heteroarylene functional group and wherein X is a nitride or a halide ion.
6. The semiconductor device of claim 5 , wherein the receptor layer is separated from the channel region by a protective layer.
7. The semiconductor device of claim 1 , wherein the receptor layer is arranged over the gate structure.
8. The semiconductor device of claim 1 , wherein the organic semiconductor layer covers the electrode pair.
9. The semiconductor device of claim 1 , wherein the electrodes are gold electrodes.
10. The semiconductor device of claim 1 , wherein the organic semiconductor layer is a self-assembled monolayer, and wherein the nitric oxide coordination complex is spin-coated onto the monolayer.
11. The semiconductor device of claim 1 , wherein the receptor layer is separated from the channel region by a protective layer.
12. The semiconductor device of claim 1 , wherein the organic semiconductor channel region comprises polyarylamine.
13. A sensing device, comprising:
a measuring chamber in communication with a fluid inlet, said measuring chamber comprising a semiconductor device according to claim 11 ;
a processor coupled to the semiconductor device for correlating a signal from the semiconductor device to a nitric oxide concentration; and
an output for providing a user with the nitric oxide concentration.
14. The sensing device of claim 13 , wherein the sensing device is a breath analyzer.
15. A method of determining a nitric oxide concentration in exhaled breath, said method comprising:
providing a breath analyzer as claimed in claim 14 ,
exhaling the breath into the inlet; and
determining the NO concentration.