Analyte detection using nanowires produced by on-wire lithography
The present invention relates to methods of detecting analytes using nanowires having nanodisk arrays. In particular, the present invention discloses methods of detecting analytes via surface enhanced Raman scattering (SERS) and employing nanowires prepared using on-wire lithography (OWL).
1. A method of assaying for a presence or a concentration of an analyte or a plurality of analytes in a sample comprising:
a) contacting the sample with a nanowire to create a mixture, wherein the nanowire comprises at least one nanodisk array comprising at least two nanodisks, each nanodisk independently having a thickness of about 20 nm to about 500 nm, and at least one gap of about 2 to about 500 nm;
b) illuminating the mixture with a radiation source; and
c) measuring a signal intensity resulting from the illumination of the mixture, wherein the intensity is correlated to the presence or concentration of the analyte in the sample.
2. The method of claim 1 wherein the nanodisk array comprises nanodisks having a thickness of about 40 to about 250 nm.
3. The method of claim 1 wherein the nanodisk array comprises gaps of about 5 to about 160 nm.
4. The method of claim 1 wherein the nanodisks are gold.
5. The method of claim 1 wherein the number of gaps in the nanodisk array is selected from the group consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10.
6. The method of claim 1 wherein the sample further comprises a detection reagent.
7. The method of claim 6 wherein the detection reagent is capable of covalently attaching to the analyte.
8. The method of claim 6 wherein the detection reagent is capable of non-covalently attaching to the analyte.
9. The method of claim 1 wherein the radiation source is a laser.
10. The method of claim 1 wherein the signal intensity is enhanced compared to a signal intensity when the sample is assayed in the absence of the nanowire.
11. The method of claim 10 wherein the signal intensity is enhanced by factor of about 10 to about 200 times more intense than a signal intensity when the sample is assayed in the absence of the nanowire.
12. The method of claim 10 wherein the signal intensity is amplified due to a plasmon resonance.
13. The method of claim 1 wherein the signal is a surface enhanced Raman scattering signal.
14. A kit for practicing the method of claim 1 comprising a plurality of nanowires, wherein each nanowire comprises at least one nanodisk array comprising at least two nanodisks, at least one gap, and a coating to hold the nanodisk arrays in the nanowire, wherein each nanodisk independently has a thickness of about 20 nm to about 500 nm, and each gap independently is about 2 to about 500 nm, and
wherein the nanodisk arrays are capable of a signal intensification due to a plasmon resonance.
15. The kit of claim 14 further comprising one or more of detection reagents or probes.