Abstract: An alcohol sensor having gas-sensitive layers made of polymers or inorganic oxides wherein a signal is read out by means of work function change which is produced in the form of a field-effect transistor.

Abstract: A sensor for detecting a gas mixture which substantially comprises air and contains one or a plurality of gases that exhibit a disadvantageous effect on living organisms, comprising: a sensor chip composed of silicon for reading out at least one signal which is generated at a sensitive substance given the presence of one or a plurality of target gases in the measurement gas, a sensitive substance applied on the sensor chip, comprising living cells, which respond to target gas, a signal processing unit for evaluating the signals of the Si chip.

Abstract: A gas-sensitive field-effect transistor may be formed from a substrate with a gas-sensitive layer and a transistor processed separately and then assembled. The substrate may be patterned to form spacers by which the height of an air gap between the transistor and the sensitive layer may be adjustable to a relatively precise degree. Formation of the spacers can be achieved by patterning the substrate using material-removal techniques. The height of the spacers may be adjusted in the layer thickness of the gas-sensitive layer and for the transistor fabricated using a CMOS process. Suitable techniques for producing recesses between the spacers include, for example, polishing, cutting, sandblasting, lithographic dry etching, or wet-chemical etching. Suitable materials for the substrate may include, for example, glass, ceramic, aluminum oxide, silicon, or a dimensionally stable polymer.

Abstract: A biosensor for detecting an antigen using an antigen/antibody coupling includes: a silicon substrate, at least one interdigital electrode pair structure that is located on the silicon substrate, the electrode pair being interspaced at a maximum distance of 1.0 ?m; a counter-electrode on the silicon substrate; a reference electrode; a first layer of protein, covering at least the interdigital electrode structure; a selective second protein layer applied to the first layer and containing a capture antibody selected specifically with respect to the antigen of interest and to which the antigen can be coupled. A sensor signal can be read on the interdigital electrode structure, if the antigen is coupled to the capture antibody by way of a sample to be analysed that comes into contact with the biosensor and a redox reactive molecule is enzymatically released on the sensor surface by an enzyme-marked detection antibody likewise coupled to the antigen.

Abstract: A gas sensor based on a field effect transistor (“FET”) evaluates both a change in work function of a gas-sensitive layer of the FET and a change in the capacitance of the layer. Thus, two physically independent signals are read from the gas-sensitive layer, each signal representing a sensitivity to a different gas. This reduces the effect of cross-sensitivities; that is, of one gas on the target gas. The underlying physical mechanisms, the first causing a change in the work function in a reaction with gases and the second causing a change in the capacitance of the sensitive layer, are widely different. Because of this, the two parameters demonstrate different gas sensitivities. If the reactions to both gases are known, the effect of the interfering gas on the sensor signal can be compensated for, and with this the concentration of the target gas can be determined.

Abstract: A gas-sensitive field-effect transistor (GasFET) for the detection or measurement of an amount of hydrogen sulfide present in ambient air includes a raised gate electrode and a transistor structure. The raised gate electrode may be formed from or coated with a gas-sensitive material such as tin oxide, or silver, silver oxide or mixtures thereof. An insulator layer may be disposed on top of the transistor structure. An air gap is formed between the gas-sensitive layer of the raised gate electrode and the insulator layer on top of the transistor structure.

Abstract: The invention relates to an FET-based gas sensor comprising a gas channel for diffusing a measuring gas to a gas-sensitive layer which is actively connected to a FET for signal readout. According to the invention, an electrochemical element is at least partially inserted into the gas channel for the electrochemical conversion of interfering gases. The arrangement is permeable to the target gas.

Abstract: Method of effecting a readout of a gas-sensitive field-effect transistor having an air gap between a gate electrode with a gas-sensitive layer and the readout transistor, in which a potential occurring on the gas-sensitive layer in the presence of a target gas is passed through a noncontacting floating gate electrode to the transistor, wherein the potential of a reference electrode, which together with the floating gate electrode generates a capacitance Cw, is tracked to the potential of the floating gate electrode in order to eliminate the capacitance Cw during the measurement.

Abstract: A gas-sensitive field-effect transistor may be formed from a substrate with a gas-sensitive layer and a transistor processed separately and then assembled. The substrate may be patterned to form spacers by which the height of an air gap between the transistor and the sensitive layer may be adjustable to a relatively precise degree. Formation of the spacers can be achieved by patterning the substrate using material-removal techniques. The height of the spacers may be adjusted in the layer thickness of the gas-sensitive layer and for the transistor fabricated using a CMOS process. Suitable techniques for producing recesses between the spacers include, for example, polishing, cutting, sandblasting, lithographic dry etching, or wet-chemical etching. Suitable materials for the substrate may include, for example, glass, ceramic, aluminum oxide, silicon, or a dimensionally stable polymer.

Abstract: A biosensor is for detecting an allergen-specific immunoglobulin E (IgE) via antigen/antibody coupling. The biosensor includes a silicon substrate and at least one interdigital electrode pair structure applied to the silicon substrate with a gap between the electrode pairs of a maximum of 1.0 ?m. A counter electrode is further applied to the silicon substrate. The biosensor also includes a reference electrode. Additionally, coatings are included on the biosensor. A first coat is made from protein coating at least the interdigital electrode structure; a selective second coat is made from protein applied over the first coat, the second coat containing a selected captor antibody; and a third coat is applied over the first coat, which contains the allergen which can couple to the captor antibody.

Abstract: An ozone sensor has an ozone-sensitive layer containing an ozone-sensitive material which is encapsulated in a polymer or in a polymer mixture or is coated by at least one polymer or polymer mixture. Advantages result from a longer service life of the ozone-sensitive materials which, because of their high hygroscopic properties, would not be stable without encapsulation or coating. Furthermore, a polymer matrix can be selectively used as a filter or in order to eliminate interfering influences.

Abstract: A volumetric flow of an analyte, including exhaled air, is fed to a gas sensor unit by used of gas flow device, which can include various sensors for the determination of nitrogen oxides. An oxidation catalyst is used when using an NO2 sensor, which converts nitrogen monoxide to nitrogen dioxide and the gas sensor unit measures the content of nitrogen dioxide. The nitrogen monoxide content is calculated from the nitrogen dioxide content. In order to eliminate cross-sensitivity moisture and ethanol are also measured. The device can be applied to the determination of nitrogen monoxide content of exhaled air.

Abstract: The invention relates to an ozone sensor having an ozone-sensitive layer containing an ozone-sensitive material which is encapsulated in a polymer or in a polymer mixture or is coated by at least one polymer or polymer mixture. Advantages result from a longer service life of the ozone-sensitive materials which, because of their high hygroscopic properties, would not be stable without encapsulation or coating. Furthermore, a polymer matrix can be selectively used as a filter or in order to eliminate interfering influences.

Abstract: An alcohol sensor having gas-sensitive layers made of polymers or inorganic oxides wherein a signal is read out by means of work function change which is produced in the form of a field-effect transistor.