Capacitive sensor and method of use
AssigneeAltratech Limited
InventorsTimothy Cummins, Brian O'Farrell
Life of this patent
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Abstract
An analyte in a liquid sample is detected using a capacitive sensor having electrodes and a sensor surface, and a signal processor. The sample is dried to reduce its liquid content, and capacitive measurements are made after the drying and preferably also before the drying. The sample may include particles, and the analyte is part of or attached to the particles, and the particles provide a major part of the capacitance change compared to absence of particles. In another example the particles are degenerative and form an integral mass upon application of heat, enhancing the extent of capacitance change.
Claims20
A method for detecting an analyte, the method comprising:
- introducing, into a region of a sensor, a sample comprising one or more bead-bound analytes of interest, wherein the region comprises a surface disposed above a plurality of electrodes and having attached entities capable of binding said analytes;
- removing components of said sample not bound to said entities;
- measuring capacitance across said region using fringe-field sensing, wherein said beads provide a major part of a capacitance change in which there is an increase in capacitance proportional with an increasing number of beads;
- detecting an amount of said analyte using the measured capacitance across said region.
An analyte sensor comprising:
- a sensing region;
- a plurality of probes attached to the sensing region, the probes designed to specifically bind a bead-bound analyte of interest;
- and
- an integrated circuit comprising a plurality of electrodes disposed below a surface of a sensing region operable to measure a change in capacitance of the sensing region using fringe-field sensing, wherein said beads provide a major part of a capacitance change in which there is an increase in capacitance proportional with an increasing number of beads.
Dependencies are inferred from the claim text.