US5814525A
Expired / Lapsed
US
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Piezoelectric biosensor with a ladder polymer substrate coating
Assignee: National Technology and Engineering Solutions of Sandia LLC
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Filing: 1996-01-25
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Granted: 1998-09-29
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Expires: 2016-01-25
Abstract
Abstract A piezoelectric biosensor substrate useful for immobilizing biomolecules in an oriented manner on the surface of a piezoelectric sensor has a ladder polymer of polyacrylonitrile. To make the substrate, a solution of an organic polymer, preferably polyacrylonitrile, is applied to the surface of a piezoelectric sensor. The organic polymer is modifying by heating the polymer in a controlled fashion in air such that a ladder polymer is produced which, in turn, forms the attachment point for the biomolecules comprising the piezoelectric biosensor.
Inventors
- 👤 Clifford L. Renschler
- 👤 Christine A. White
- 👤 Robert M. Carter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 13:28
CPC Classifications
C; C12; C12Q; C12Q1/00; C12Q1/001; C12Q1/002; G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/53; G01N33/543; G01N33/54366; G01N33/54373; Y; Y10; Y10S; Y10S436/00; Y10S436/806
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
44 words
A piezoelectric-based biosensor, comprising: a piezoelectric sensing element; a substrate coating on said piezoelectric sensing element, wherein the substrate coating comprises a ladder polymer; and at least one biomolecule immobilized onto said substrate coating for the purpose of sensing at least one analyte species.
Claim 2
Dependent Claim
44 words
A piezoelectric-based biosensor, comprising: a piezoelectric sensing element; a substrate coating on said piezoelectric sensing element, wherein the substrate coating comprises a ladder polymer; and at least one biomolecule immobilized onto said substrate coating for the purpose of sensing at least one analyte species.
Claim 3
Dependent Claim
11 words
The biosensor of claim 1, wherein the ladder polymer is polyacrylonitrile.
Claim 4
Dependent Claim
36 words
The biosensor of claim 1, wherein the ladder polymer has been thermally modified by heating the polymer to a temperature of about 220° C. and maintaining the polymer at about 220° C. for about 16 hours.
Claim 5
Dependent Claim
27 words
The biosensor of claim 1 wherein each biomolecule has a tail end comprising carboxylic acid groups, the biomolecules being oriented on the substrate in the same direction.
Claim 6
Dependent Claim
18 words
The biosensor of claim 4 wherein the ladder polymer provides a --C═N-- site for bonding said tail end.
Claim 7
Dependent Claim
13 words
The biosensor of claim 1, wherein said substrate coating comprises a single layer.
Claim 8
Independent Claim
139 words
A method for providing a substrate coating on a piezoelectric element for a piezoelectric-based biosensor, comprising the steps of: forming an organic polymer solution by dissolving in a solvent an organic polymer capable of forming a series of aromatic ring structures connected by links around which no bond rotation can take place except by bond breaking; equilibrating the organic polymer solution at a controlled relative humidity; disposing the equilibrated organic polymer solution onto the surface of a piezoelectric element to form a polymer coating; evaporating the solvent from the polymer coating at a controlled relative humidity; and modifying the organic polymer coating by heating the polymer coating at a controlled rate in air to a selected temperature, maintaining the temperature, thereby transforming the organic polymer to a ladder polymer substrate coating, and cooling the coating at a controlled rate.
Claim 9
Independent Claim
139 words
A method for providing a substrate coating on a piezoelectric element for a piezoelectric-based biosensor, comprising the steps of: forming an organic polymer solution by dissolving in a solvent an organic polymer capable of forming a series of aromatic ring structures connected by links around which no bond rotation can take place except by bond breaking; equilibrating the organic polymer solution at a controlled relative humidity; disposing the equilibrated organic polymer solution onto the surface of a piezoelectric element to form a polymer coating; evaporating the solvent from the polymer coating at a controlled relative humidity; and modifying the organic polymer coating by heating the polymer coating at a controlled rate in air to a selected temperature, maintaining the temperature, thereby transforming the organic polymer to a ladder polymer substrate coating, and cooling the coating at a controlled rate.
Claim 10
Dependent Claim
21 words
The method of claim 7 wherein the ladder polymer substrate coating has a thickness between about 200 Å and 2 μm.
Claim 11
Dependent Claim
14 words
The method of claim 7 wherein the piezoelectric element is a quartz crystal microbalance.
Claim 12
Dependent Claim
11 words
The method of claim 7 wherein the organic polymer is polyacrylonitrile.
Claim 13
Dependent Claim
11 words
The method of claim 7 wherein the solvent is dimethyl formamide.
Claim 14
Dependent Claim
15 words
The method of claim 7 wherein the relative humidity is between about 40% and 80%.
Claim 15
Dependent Claim
12 words
The method of claim 7 wherein the relative humidity is about 80%.
Claim 16
Dependent Claim
12 words
The method of claim 7 wherein said step of disposing is spin-casting.
Claim 17
Dependent Claim
38 words
The method of claim 7 wherein said step of modifying comprises heating the organic polymer coating in air to a temperature of about 220° C., and maintaining the polymer temperature of about 220° C. for about 16 hours.
Claim 18
Dependent Claim
14 words
A biosensor having a sensor substrate coating prepared by the method of claim 7.
Claim 19
Independent Claim
141 words
A method for making a piezoelectric biosensor, comprising: dissolving in a solvent an organic polymer capable of forming a series of aromatic ring structures connected by links around which no bond rotation can take place except by bond breaking; equilibrating the organic polymer solution at a controlled relative humidity; disposing the equilibrated organic polymer solution onto the surface of a piezoelectric element to form a polymer coating; evaporating the solvent from the polymer coating at a controlled relative humidity; modifying the organic polymer coating by heating the polymer coating at a controlled rate in air to a selected temperature, maintaining the temperature, thereby transforming the organic polymer to a ladder polymer substrate coating, and cooling the coating at a controlled rate; and immobilizing one or more biomolecules onto said substrate coating for the purpose of sensing one or more analyte species.
Claim 20
Independent Claim
141 words
A method for making a piezoelectric biosensor, comprising: dissolving in a solvent an organic polymer capable of forming a series of aromatic ring structures connected by links around which no bond rotation can take place except by bond breaking; equilibrating the organic polymer solution at a controlled relative humidity; disposing the equilibrated organic polymer solution onto the surface of a piezoelectric element to form a polymer coating; evaporating the solvent from the polymer coating at a controlled relative humidity; modifying the organic polymer coating by heating the polymer coating at a controlled rate in air to a selected temperature, maintaining the temperature, thereby transforming the organic polymer to a ladder polymer substrate coating, and cooling the coating at a controlled rate; and immobilizing one or more biomolecules onto said substrate coating for the purpose of sensing one or more analyte species.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-09-28 | 2002-03-30 | 2002-09-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-09-28 | 2006-03-30 | 2006-09-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-09-28 | 2010-03-30 | 2010-09-29 | $7700.00 | Window Closed / Lapsed |