DNA-decorated graphene chemical sensors
The present invention provides a broad response single-stranded DNA-graphene chemical sensor device. The present invention also provides methods for improving the ability of graphene to work as a chemical sensor by using single-stranded DNA as a sensitizing agent.
1. A method, comprising:
with a nucleic acid functionalized clean graphene sensor device that comprises (i) an insulator thin-film disposed directly adjacent to a back-gate substrate, (ii) at least one positive electrode disposed directly adjacent to said insulator thin-film, opposite to said back-gate substrate, (iii) at least one negative electrode disposed directly adjacent to said insulator thin-film, opposite to said back-gate substrate, and (iv) the clean graphene being disposed between, and in electrical communication with, said positive and negative electrodes and the clean graphene being single-atom thick graphene,
contacting the nucleic acid functionalized clean graphene sensor device with a medium;
monitoring a conductance of the nucleic acid functionalized clean graphene; and
correlating a change in the conductance to the presence, absence, or concentration of molecules, or any combination thereof.
2. The method of claim 1 , wherein said contacting is accomplished by flowing the medium over said sensor device.
3. The method of claim 1 , wherein the medium is a solid, liquid, gas, or combination thereof.
4. The method of claim 3 , wherein the medium comprises analytes.
5. The method of claim 1 , whereby monitoring the conductance occurs when applying a 1 mV bias and holding the gate voltage at 0.
6. The method of claim 1 , whereby the conductance of the nucleic acid functionalized clean graphene is monitored via electrodes, wherein the electrodes comprise gold and chromium.
7. The method of claim 1 , further comprising:
contacting a plurality of the nucleic acid functionalized clean graphene sensor devices with the medium, wherein each of the sensor devices is functionalized with a different nucleic acid;
monitoring the conductance of each sensor device; and
correlating a change in conductance into each device to the presence, absence, or concentration of molecules, or any combination thereof.
8. The method of claim 7 , further comprising using a data processing system to send a control signal and receive a data input signal from at least one of the sensor devices, and using a pattern recognition data processing system to detect the presence, absence, or concentration of several molecular species.
9. The method of claim 1 , wherein the nucleic acid comprises single-stranded DNA.
10. The method of claim 1 , wherein the device has a hole mobility of 500 cm 2 /V·s to 200,000 cm 2 /V·s.
11. The method of claim 1 , wherein the device has a hole mobility of 500 cm 2 /V·s to 5000 cm 2 /V·s.
12. The method of claim 1 , wherein the device has a hole mobility of 1600 cm 2 /V·s to 5000 cm 2 /V·s.
13. The method of claim 1 , wherein the device has a doped charge carrier density of about 0 to about 1×10 15 /cm 2 at zero gate voltage.
14. The method of claim 1 , wherein the medium comprises a gas, a liquid, a tissue, a head space, or an environmental sample.
15. The method of claim 9 , wherein the single-stranded DNA is according to SEQ ID NO. 1.
16. The method of claim 9 , wherein the single-stranded DNA is according to SEQ ID NO. 2.