Microcantilever sensor
First Claim
1. A microcantilever for detecting at least one analyte in a fluid medium comprising:
- a deflectable arm having one end fixedly coupled to a substrate, said arm being a sensing material on disposed in an initially stationary rest position capable of deflecting responsive to a volumetric change of a subjacent sensing element contacting said arm, and detecting means capable of measuring the deflection of said arm out of said rest position.
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Accused Products
Abstract
An apparatus and method for sensing chemical and/or biological analytes includes a deflectable arm of a microcantilever formed over and contacting a sensing element. A gaseous or liquid medium which may include the analyte being detected, is introduced to the sensing element. The sensing element undergoes volumetric expansion or contraction in the presence of the analyte sought to be detected, typically by adsorbing the analyte. The volumetric change of the sensing element causes the deflectable arm to deflect. The deflectable arm includes at least one measurable physical property which changes when the arm deflects. Detecting means are provided to measure the change in the physical property to determine the presence and amount of analyte present. An array of microcantilevers in which each microcantilever is dedicated to detecting a particular analyte which may be included in the medium, is also provided.
133 Citations
34 Claims
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1. A microcantilever for detecting at least one analyte in a fluid medium comprising:
a deflectable arm having one end fixedly coupled to a substrate, said arm being a sensing material on disposed in an initially stationary rest position capable of deflecting responsive to a volumetric change of a subjacent sensing element contacting said arm, and detecting means capable of measuring the deflection of said arm out of said rest position. - View Dependent Claims (2, 3, 4, 5, 8, 9, 10, 11, 12, 15, 16, 17, 18, 19, 20, 21)
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6. A microcantilever for detecting at least one analyte in a fluid medium comprising:
a deflectable arm having one end fixedly coupled to a substrate, said arm being disposed in a rest position capable of deflecting responsive to a volumetric change of a subjacent sensing element contacting said arm, and detecting means capable of measuring the deflection of said arm out of said rest position, wherein said arm includes a piezoresistive member formed one of therein and thereon and said detecting means includes an electrical circuit capable of measuring a change in resistance of said piezoresistive member due to said deflection, and wherein said piezoresistive member comprises barium titanate.
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7. A microcantilever for detecting at least one analyte in a fluid medium comprising:
a deflectable arm having one end fixedly coupled to a substrate, said arm being disposed in a rest position capable of deflecting responsive to a volumetric change of a subjacent sensing element contacting said arm, and detecting means capable of measuring the deflection of said arm out of said rest position in which said deflectable arm overhangs an edge of said substrate and said sensing element is disposed on a further substrate.
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13. A microcantilever for detecting at least one analyte in a fluid medium comprising:
a deflectable arm having one end fixedly coupled to a substrate, said arm being disposed in a rest position capable of deflecting responsive to a volumetric change of a subjacent sensing element contacting said arm, and detecting means capable of measuring the deflection of said arm out of said rest position wherein said sensing element comprises a biological sensor formed of layered biological molecules capable of adsorbing said at least one analyte and volumetrically expanding in the vertical direction as a result of said adsorption, and in which said biological sensor comprises a thiolated single strand DNA disposed on a gold substrate. - View Dependent Claims (14)
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22. An array of microcantilevers for detecting analytes, comprising:
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a plurality of discrete sensing elements formed on a surface;
a corresponding plurality of deflectable arms each being disposed in a rest position, each having one end fixedly coupled to a substrate and an overhang portion situated superjacent a corresponding sensing element and contacting said corresponding sensing element, each deflectable arm capable of deflecting responsive to a volumetric change in said corresponding sensing element; and
detecting means capable of measuring the deflection of each deflectable arm out of each said rest position. - View Dependent Claims (23, 25, 26, 27, 28)
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24. An array of microcantilevers for detecting analytes, comprising:
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a plurality of discrete sensing elements formed on a surface;
a corresponding plurality of deflectable arms each being disposed in a rest position, each having one end fixedly coupled to a substrate and an overhang portion situated superjacent a corresponding sensing element and contacting said corresponding sensing element, each deflectable arm capable of deflecting responsive to a volumetric change in said corresponding sensing element; and
detecting means capable of measuring the deflection of each deflectable arm out of each said rest position wherein each sensing element is different from the other sensing elements, and in which said deflectable arms each have one end fixedly coupled to a common substrate and said surface is formed on a further substrate situated adjacent said common substrate.
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29. A method for detecting an analyte within a fluid medium, comprising:
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providing a deflectable microcantilever arm having one end fixedly coupled to a substrate, said microcantilever arm disposed in a rest position;
forming a sensing element subjacent said arm and contacting an underside of said arm, said sensing element capable of at least one of vertical swelling and vertical contraction responsive to the presence of said analyte, said vertical swelling causing said microcantilever arm upward deflection and said vertical contraction causing said microcantilever arm downward deflection;
introducing a fluid medium containing said analyte to said sensing element, said medium being one of a liquid and a vapor; and
measuring said deflection of said microcantilever arm out of said rest position. - View Dependent Claims (31, 32, 33, 34)
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30. A method for detecting an analyte within a fluid medium, comprising:
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providing a deflectable microcantilever arm having one end fixedly coupled to a substrate, said microcantilever arm disposed in a rest position;
forming a sensing element subjacent said arm and contacting an underside of said arm, said sensing element capable of at least one of vertical swelling and vertical contraction responsive to the presence of said analyte, said vertical swelling causing said microcantilever arm upward deflection and said vertical contraction causing said microcantilever arm downward deflection;
introducing a fluid medium containing said analyte to said sensing element, said medium being one of a liquid and a vapor; and
measuring said deflection of said microcantilever arm out of said rest position wherein said microcantilever arm includes at least one measurable physical property which changes when said microcantilever arm deflects and said measuring comprises measuring a change in said at least one measurable physical property.
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Specification