Detection of cardiac troponin or biological markers via shear horizontal surface acoustic wave biosensor using a wet-dry bioanalytical technique

Inventors

Shachar, Yehoshua • Thomas, Marlon S.

Assignees

Autonomous Medical Devices Inc

Abstract

The illustrated embodiments include a method of operating a SAW sensor to detect a sample in a fluid which includes the steps of: providing a SAW sensor with a functionalized detection lane in a handheld, portable assay device and sensor system; maintaining the functionalized detection lane of the SAW sensor dry until the sample is fluidically disposed in the detection lane; fluidically disposing the sample in the functionalized detection lane; removing fluid the functionalized detection lane to concentrate the sample in the functionalized detection lane to increase the probability of a specific antibody-antigen interaction; washing the functionalized detection lane so that substantially only the specific antigen-antibody interaction remains in the functionalized detection lane; removing fluid from the functionalized detection lane again; and measuring concentration of the sample while the functionalized detection lane is fluid-free.

Core Innovation

The invention relates to a method of operating a SAW sensor to detect an analyte suspended in a first fluid sample taken from a patient using a handheld, portable assay device and sensor system. The method provides a SAW sensor with at least one functionalized detection lane in which the functionalized detection lane consists of a composite thin film coated with an antibody and disposed over a substrate. The fluid sample is fluidically disposed in the functionalized detection lane to enable antibody-analyte complex formation at the detection surface.

A key operation is concentrating the analyte at a surface of the functionalized detection lane so as to concentrate the first sample and increase the probability of forming a complex comprising an analyte and an antibody bound to the functionalized detection lane. The SAW signal is confined to an interface between the first fluid sample and the composite thin film, so that the sensing is performed at the boundary where complex formation occurs. The method then measures a concentration of the analyte originally suspended in the first fluid sample within the formed complex at the interface between the first fluid sample and the composite thin film.

The described sensor configuration includes a LiTaO3 substrate with a silicon dioxide waveguide/scaffold over interdigital electrodes, and antibody immobilization on the composite thin film. The accompanying description further supports differential measurement behavior using reference lanes and supports multiplexed biomarker measurement, including cardiac troponin, creatine kinase, and myoglobin.

Claims Coverage

The independent claim defines operating a handheld portable SAW sensor with an antibody-functionalized composite thin-film detection lane to concentrate and detect patient analytes by measuring analyte complex concentration at an interface. The independent claim includes multiple inventive functional elements that collectively confine the SAW signal to the interface and quantify analyte concentration in the formed complex, with dependent claim refinements specifying analyte targets and multi-lane, repeated-sample, and calibrated dynamic range constraints.

Overall, the claim set covers a handheld SAW biosensing workflow where an antibody-coated composite thin-film detection lane promotes concentrated analyte-antibody complex formation, with the SAW signal confined to the sample/thin-film interface and analyte concentration measured within the formed complex. Dependent claim refinements specify quantitative constraints via a calibrated dynamic range, analyte-specific embodiments such as troponin I, multiplexed biomarker testing, simultaneous multi-lane operation, and repeated patient sampling with measurement based on a predetermined analyte mass.

Stated Advantages

Documented Applications