Biosensor platform for rapid diagnostic testing
Inventors
Hnasko, Robert M. • Jackson, Eric S. • Haff, Ronald P. • URAMOTO, SUSAN
Assignees
US Department of Agriculture USDA
Publication Number
US-11415578-B2
Publication Date
2022-08-16
Expiration Date
2039-06-18
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Abstract
The bio sensor platform is a rapid point-of-care (POC) device wherein detection of a target analyte from a liquid or solid substrate is performed in a single step using a fully integrated disposable test system that includes a test strip immunoassay. In operation, a user initiates the test by rupturing the bottom of a liquid-filled analyte capsule seated in a capsule sleeve. A small volume of liquid flows by capillary action from the capsule sleeve and through a restrictor port to a test strip chamber where contact with the absorptive sample pad of the test strip (among other things) moves liquid by capillary action upwardly through the test strip. The detection of the target analyte is resolved by the test strip reagents and the test results are obtained at a test result window where a portion of the test strip is exposed to the user.
Core Innovation
The invention is a modular biosensor platform that integrates all necessary assay components in a small, single-use disposable test system designed for rapid immunoassay detection of target analytes from liquid or solid substrates. This system features an outer sleeve with a liquid-filled capsule and an immunochromatographic test strip chamber connected by a restrictor port. The user initiates testing by rupturing the capsule, allowing liquid analyte to flow through the restrictor port to a test strip where capillary action draws the liquid upward through layered test strip materials to produce test results visible in a window.
The system includes a resilient, self-adjusting flex plate that presses on overlapping layers of the test strip, maintaining position and facilitating liquid transfer between materials without impeding flow. The modular design allows interchangeable components and compatibility with digital reader tools, enabling rapid, accurate, single-step point-of-care testing with minimal user training. The system's construction supports testing of a wide range of analytes from various sample types while minimizing user error common in multi-step lateral flow assay procedures.
The problem addressed is the complexity and user error associated with existing lateral flow assay kits which require multi-step procedures, separate components such as liquid extraction buffers, and precise liquid delivery mechanisms. Existing devices often involve multiple poorly integrated parts that are cumbersome, prone to user error, and less suitable for field testing of solid substrates or buffered liquids needing volume control. This invention provides a fully integrated, simplified, and robust platform that overcomes these drawbacks by combining sample extraction, precise liquid delivery, and detection in a single disposable unit.
Claims Coverage
The patent contains multiple independent claims focusing on a modular biosensor system and methods of testing analytes. The main inventive features cover structural components facilitating controlled liquid flow, capillary action, and test strip stabilization within the system.
Integrated modular biosensor system structure
The system comprises a sleeve with a capsule opening and test strip chamber, a liquid-filled capsule that slides into the sleeve, and a test strip that slides into the chamber. A resilient flex plate extends from the interior wall of the chamber, contacts the test strip to maintain position and facilitates liquid transfer between test strip materials. The system is structured so that rupturing the capsule causes analyte liquid to flow from the capsule to the test strip bottom and upward past the flex plate, displaying results.
Restrictor port creating capillary action
A restrictor port positioned between the capsule opening and test strip chamber, which in combination with the chamber and bottom portion of the test strip forms a structural relationship that creates a capillary force wicking analyte fluid from the capsule through the restrictor port and up the test strip. The test strip at least partially blocks and abuts the restrictor port, which is positioned above the chamber bottom.
Capsule securing and initiation mechanism
The capsule and sleeve have corresponding threads or grooves so that test initiation occurs when a user screws the capsule into the sleeve, rupturing the capsule bottom via a spike in the sleeve. Alternatively, the capsule may have a frangible bottom broken by twisting without threads.
Flex plate pressure on test strip layers
The resilient flex plate applies pressure specifically on areas where test strip layers (sample pad, conjugate release pad, and nitrocellulose membrane) overlap or interface, structurally facilitating fluid communication between these layers without impeding analyte flow upward.
Test result window visibility
A test window aperture in the sleeve front panel positioned so a user can view the test strip in the test strip chamber to observe test results.
Methods of testing analytes
Methods for testing liquid and solid analytes using the modular biosensor system including adding analyte to the capsule, initiating the test by causing liquid flow to the test strip, and reading results visually or electronically.
The independent claims collectively protect the integrated modular biosensor system with a capsule and test strip housed within a sleeve, featuring a flex plate to maintain test strip positioning and liquid transfer, a restrictor port to create capillary flow, mechanisms to initiate liquid release from the capsule, and methods for testing analytes using this system to rapidly obtain test results.
Stated Advantages
Allows single-step, rapid, and accurate point-of-care testing with minimal user training.
Integrates sample extraction, liquid delivery, and immunoassay testing into a compact disposable platform.
Minimizes end-user error common in multi-step lateral flow assay procedures.
Compatible with most standard lateral flow test strips and designed for ease of manufacturing and assembly.
Supports testing of analytes from both liquid and solid substrates.
Designed for use with digital reader tools enabling data recording and analysis.
Documented Applications
Rapid point-of-care testing for allergens, pathogens, toxins, adulterants, and environmental contaminants in health and food safety contexts.
Detection of target analytes from farm to fork, including agriculture testing involving solid to liquid sample extraction and pH buffering.
Human health testing such as pregnancy hormone detection and illicit drug testing via urine samples.
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