Disclosed herein are biosensors for the detection of airborne biomolecules. The biosensors include a housing, a sensing component, and optionally a sample capture component. The biosensors may utilize a gel-based detection platform.
1. A biosensor for detecting the presence and/or amount of a biomolecule in a sample, comprising:
a) a housing;
b) a sensing component, the sensing component comprising:
(i) a string-like material contacting an electrolytic gel;
(ii) colloidal gold nanoparticles linked to the string-like material, wherein the nanoparticles are each coated with a self-assembling monolayer (“SAM”), and wherein a portion of the SAM on the nanoparticles links the nanoparticles to the string-like material and another portion of the SAM on the nanoparticles links the nanoparticles to a capture molecule;
(iii) at least two electrodes in contact with the electrolytic gel and configured for impedance detection across the electrolytic gel;
c) an impedance measurement circuit coupled to the electrodes of the sensing component;
wherein the biosensor is configured to detect the presence and/or amount of the biomolecule in a dry sample in a non-liquid detection reaction.
2. The biosensor of claim 1 , wherein the sensing component is configured to sense an air sample.
3. The biosensor of claim 1 , wherein the capture molecule comprises an antibody.
4. The biosensor of claim 1 , wherein the capture molecule comprises an antibody that specifically binds to a mold antigen.
5. The biosensor of claim 1 , wherein the capture molecule comprises an antibody that specifically binds to an antigen which has been bound to another antibody.
6. The biosensor of claim 1 , wherein the capture molecule comprises a monoclonal antibody that specifically binds to a mold antigen, wherein the mold is selected from the group consisting of the genus Chaetomium, Aspergillus, Penicillium , and Stachybotrys.
7. The biosensor of claim 1 , wherein the capture molecule comprises a monoclonal antibody that specifically binds to a tuberculosis antigen.
8. The biosensor of claim 1 , comprising a sample capture device configured to direct sample onto the sensing component.
9. The biosensor of claim 1 , wherein the sensing component is removable.
10. The biosensor of claim 1 , wherein the sensing component is configured for a single use.
11. The biosensor of claim 1 , wherein the pH of the sensing component electrolytic gel is controlled by a bias dc voltage and configured for multiple use.
12. The biosensor of claim 1 , wherein the electrolytic gel comprises agarose.
13. The biosensor of claim 1 , wherein the biosensor comprises a housing which is sized to be handheld while in use.
14. The biosensor of claim 1 , comprising a memory configured to store a set of impedance parameters, wherein the impedance parameters are specific to the biomolecule to be bound to the capture molecule.
15. The biosensor of claim 14 , wherein the number of impedance parameters stored in the memory is less than 10.
16. The biosensor of claim 1 , wherein the sensing component comprises a porous string-like medium immersed in the electrolytic gel.
17. The biosensor of claim 1 , wherein the sensing component comprises a solid string-like material.
18. The biosensor of claim 8 , wherein the sample capture device comprises a piezoelectric fan.
19. The biosensor of claim 1 , wherein the SAM is a bifunctional molecule comprising both a thiol and a silane functional group.
20. A biosensor for detecting the presence and/or amount of a biomolecule in a sample, comprising:
a) a housing;
b) a sensing component, the sensing component comprising:
(i) a string-like material contacting an electrolytic gel;
(ii) colloidal gold nanoparticles linked to the string-like material, wherein the nanoparticles are each coated with a self-assembling monolayer (“SAM”), and wherein a portion of the SAM on the nanoparticles links the nanoparticles to the string-like material and another portion of the SAM on the nanoparticles links the nanoparticles to a capture molecule;
(iii) at least two electrodes in contact with the electrolytic gel and configured for impedance detection across the electrolytic gel;
c) an impedance measurement circuit coupled to the electrodes of the sensing component;
wherein the biosensor is configured to detect the presence and/or amount of the biomolecule in the sample in a non-liquid detection reaction.
21. The biosensor of claim 20 , wherein the sensing component is configured to sense an air sample.
22. The biosensor of claim 20 , wherein the capture molecule comprises an antibody.
23. The biosensor of claim 20 , wherein the capture molecule comprises an antibody that specifically binds to a mold antigen.
24. The biosensor of claim 20 , wherein the SAM is a bifunctional molecule comprising both a thiol and a silane functional group.
25. A method for detecting the presence and/or amount an airborne biomolecule of interest, the method comprising:
a) collecting an air sample that may contain the biomolecule of interest in the biosensor of claim 1 ;
b) contacting the air sample with the biosensor sensing component;
c) contacting the biomolecule of interest, if present, with the capture molecule of the sensing component;
d) identifying a change in impedance that is characteristic of the presence and/or amount of the biomolecule in contact with the capture molecule, thereby detecting the presence and/or amount of the biomolecule.
26. The method of claim 25 , wherein the time elapsed between contacting the air sample with the sensing component and identifying a change in impedance characteristic of the presence and/or amount of the biomolecule is less than about 1 minute.
27. The method of claim 25 , wherein the air sample is collected from the interior of a building, and the biomolecule of interest is a mold or is derived from a mold.
28. The method of claim 25 , wherein the air sample is collected immediately above a water supply, and the biomolecule of interest comprises Cryptosporidiidae cryptosporidium or is derived from Cryptosporidiidae cryptosporidium .
29. The method of claim 25 , wherein the air sample is collected outdoors.
30. The method of claim 25 , wherein the capture molecule comprises a monoclonal antibody attached to a different antibody.