HANDHELD MICROCANTILEVER-BASED SENSOR FOR DETECTING TOBACCO-SPECIFIC NITROSAMINES
0 Assignments
0 Petitions
Accused Products
Abstract
A method and system for detecting tobacco-specific nitrosamines. The method includes exposing at least one microcantilever beam to a medium, which may contain tobacco-specific nitrosamines, and measuring a deflection of the microcantilever beam, wherein the deflection indicates a presence of tobacco-specific nitrosamines in the medium. The at least one microcantilever beam can include a silicon base layer and a gold-coated receptor layer with a plurality of thiol molecules having a sulfur head and carboxyl-terminated group. The at least one microcantilever beam can include a silicon base layer and a metal or metal oxide coated receptor layer. Alternatively, the microcantilever beam can be formed by co-absorbing tobacco-specific nitrosamines and silane molecules on a silicon microcantilever surface, wherein the template molecules of tobacco-specific nitrosamines physically co-adsorb between the silane molecules. The template molecules of tobacco-specific nitrosamines are then washed away with a solvent to form a silane monolayer having tobacco-specific nitrosamine cavities.
-
Citations
24 Claims
-
1. (canceled)
-
2. (canceled)
-
3. (canceled)
-
4. (canceled)
-
5. (canceled)
-
6. (canceled)
-
7. (canceled)
-
8. (canceled)
-
9. (canceled)
-
10. A handheld microcantilever-based sensor system useful for identifying tobacco-specific nitrosamines comprising:
-
at least one microcantilever beam having a receptor layer and a piezo-resistor, wherein exposure of the receptor layer to a medium causes a deflection of the microcantilever beam and the piezo-resistor converts the deflection into an electrical signal; and a detection system, which reads the electrical signal. - View Dependent Claims (11, 13, 22)
-
-
12. (canceled)
-
14. A method of functionalizing a microcantilever beam having a piezo-resistor, comprising:
-
coating a microcantilever beam with a receptor layer, wherein exposure of the receptor layer to a medium causes a deflection of the microcantilever beam; wherein the piezo-resistor converts the deflection into an electrical signal. - View Dependent Claims (23, 24)
-
-
15. The method of claim 15, wherein:
-
(a) the microcantilever beam comprises a silicon base layer and the receptor layer having a gold coating; (b) the receptor layer is formed by depositing a plurality of thiol molecules having a sulfur head and a carboxyl-terminated group onto the gold-coated receptor layer, and forming a monolayer of thiol molecules with the carboxyl-terminated group on the gold-coated receptor layer of the microcantilever beam, wherein the microcantilever beam undergoes a chemical reaction when exposed the medium; (c) the microcantilever beam has a silicon base layer, the receptor layer has a metal or metal oxide coating, the receptor layer comprises aluminum (Al), platinum (Pt), or palladium (Pd), and the at least one microcantilever undergoes deflection due to an interaction between the metal or metal oxide coating and the medium; (d) the receptor layer is formed by co-absorbing tobacco-specific nitrosamines and silane molecules on a surface of the microcantilever beam wherein template molecules of tobacco-specific nitrosamines physically co-adsorb between the silane molecules, and washing away the template molecules of tobacco-specific nitrosamines with a solvent to form a silane monolayer having tobacco-specific nitrosamine cavities; (e) one side of the microcantilever beam includes silane molecules and the other side includes a gold coating having a plurality of thiol molecules having a sulfur head group and a methyl-terminated group, which blocks absorption of the silane molecules; (f) the medium is in either a liquid or a gas phase; (g) the piezo-resistor comprises a highly doped silicon layer of the microcantilever beam; (h) the deflection changes electrical resistivity of the piezo-resistor; and
/or(i) the deflection is caused by a physical or chemical reaction of the receptor layer and tobacco-specific nitrosamines in the medium, and/or a volume change of the receptor layer.
-
- 16. (canceled)
-
18. (canceled)
-
19. (canceled)
-
20. (canceled)
Specification