Fet sensor with specially configured gate electrode for the highly sensitive detection of analytes
First Claim
1. A sensor for the detection of an analyte, the sensor comprisinga substrate forming a first plate of a first capacitor,a source contact region on the substrate,a drain contact region on the substrate,a gate oxide of a transistor on the substrate between the source contact region and the drain contact region and forming an insulator of the first capacitor,a gate electrode having inner and outer faces, the inner face being smaller than the outer face and forming a second plate of the first capacitor, the outer face forming a first plate of a second capacitor connected in series with the first capacitor, the gate-electrode inner face contacting the gate oxide over a predetermined inner contact area;
- an electrically insulating detection electrode forming an insulator of the second capacitor and having inner and outer faces, the detection-electrode inner face contacting the gate-electrode outer face;
an immobilized receptor fixed on the detection-electrode outer face for detecting a presence of the analyte and forming a second plate of the second capacitor; and
an insulator body potting all of the source contact region, drain contact region, gate electrode, and gate oxide and the detection electrode except at the detection-electrode outer face carrying the immobilized receptor to form a series circuit of the two capacitors and increase a charge density toward the transistor to enhance a detection sensitivity of the transistor.
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Accused Products
Abstract
Disclosed is a sensor comprising a substrate, a source contact region, a drain contact region, and the gate oxide of a transistor. A gate electrode is disposed between the gate oxide and a detection electrode made of a nonconducting material. The contact area Asens between the gate electrode and the detection electrode is larger than the contact area Agate between the gate electrode and the gate oxide, whereby the receptor can be immobilized on the surface of the detection electrode in a technically simple manner while the small contact area Agate between the gate electrode and the transistor provides for high sensitivity for detecting the analyte. According to the inventive method for detecting at least one analyte, at least one analyte is brought into contact with a receptor immobilized at the detection electrode so as to modify the electrical charge at the surface of the detection electrode. The analyte is detected by detecting the modified voltage in the transistor.
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Citations
10 Claims
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1. A sensor for the detection of an analyte, the sensor comprising
a substrate forming a first plate of a first capacitor, a source contact region on the substrate, a drain contact region on the substrate, a gate oxide of a transistor on the substrate between the source contact region and the drain contact region and forming an insulator of the first capacitor, a gate electrode having inner and outer faces, the inner face being smaller than the outer face and forming a second plate of the first capacitor, the outer face forming a first plate of a second capacitor connected in series with the first capacitor, the gate-electrode inner face contacting the gate oxide over a predetermined inner contact area; -
an electrically insulating detection electrode forming an insulator of the second capacitor and having inner and outer faces, the detection-electrode inner face contacting the gate-electrode outer face; an immobilized receptor fixed on the detection-electrode outer face for detecting a presence of the analyte and forming a second plate of the second capacitor; and an insulator body potting all of the source contact region, drain contact region, gate electrode, and gate oxide and the detection electrode except at the detection-electrode outer face carrying the immobilized receptor to form a series circuit of the two capacitors and increase a charge density toward the transistor to enhance a detection sensitivity of the transistor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification
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- Resources
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Current AssigneeForschungszentrum Jã¼Lich GmbH (Bundesrepublik Deutschland)
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Original AssigneeForschungszentrum Jã¼Lich GmbH (Bundesrepublik Deutschland)
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InventorsOdenthal, Margarete, Offenhäusser, Andreas, Lüth, Hans, Goryll, Michael, Moers, Jürgen
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Primary Examiner(s)YANG, NELSON C
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Application NumberUS10/499,751Publication NumberTime in Patent Office2,558 DaysField of Search204/461US Class Current435/287.1CPC Class CodesC12Q 1/005 involving specific analytes...G01N 2333/904 acting on CHOH groups as do...G01N 2333/908 acting on hydrogen peroxide...G01N 27/4145 specially adapted for biomo...G01N 33/5438 ElectrodesG01N 33/551 the carrier being inorganicG01N 33/552 Glass or silica
