Systems and methods for detection and quantification of analytes
Devices, systems, and methods for detecting molecules of interest within a collected sample are described herein. In certain embodiments, self-contained sample analysis systems are disclosed, which include a reusable reader component, a disposable cartridge component, and a disposable sample collection component. In some embodiments, the reader component communicates with a remote computing device for the digital transmission of test protocols and test results. In various disclosed embodiments, the systems, components, and methods are configured to identify the presence, absence, and/or quantity of particular nucleic acids, proteins, or other analytes of interest, for example, in order to test for the presence of one or more pathogens or contaminants in a sample.
1. A sample analysis cartridge comprising:
an input tunnel extending from an aperture on a sample analysis cartridge surface of the sample analysis cartridge, the input tunnel configured to receive a sample collection device;
a reservoir positioned at a distal end of the input tunnel, the reservoir configured to hold a fluid and including a bottom floor defining a lowermost portion of the reservoir and an outlet;
an analysis channel comprising an analysis zone, the analysis channel positioned adjacent to the reservoir and extending from the reservoir, the analysis channel comprising a continuous hydrophilic surface extending between the reservoir to the analysis zone that facilitates continuous capillary flow of the fluid from the reservoir and into the analysis zone, a wall of the analysis channel that extends from the reservoir to the analysis zone defined by a circuit board; and
an electrochemical sensor at least partially disposed on the circuit board and within the analysis channel in a position to be exposed to the fluid having a sample and reagents mixed therein from the reservoir, the electrochemical sensor comprising a working electrode having a working electrode surface chemically modified by a thiolated ethylene glycol;
wherein the bottom floor of the reservoir is sloped towards the outlet and configured to encourage flow of the fluid within the reservoir to the outlet.
2. The sample analysis cartridge of claim 1 , further comprising a substrate reservoir configured to hold a substrate fluid comprising a substrate,
wherein the analysis channel is further configured to receive the substrate fluid from the substrate reservoir such that the reagents from the reservoir localized over the working electrode react with the substrate at the working electrode to generate signals detectable by the working electrode indicative of at least one of a presence, absence, or quantity of a target analyte in the sample.
3. The sample analysis cartridge of claim 2 , further comprising a wash reservoir configured to hold a wash fluid,
wherein the analysis channel is further configured to receive the wash fluid from the wash reservoir prior to receipt of the substrate fluid from the substrate reservoir.
4. A kit comprising the sample analysis cartridge of claim 1 and a reader configured to be electrically coupled to the sample analysis cartridge.
5. The kit of claim 4 , wherein the reader comprises a magnet configured to magnetically hold the reagents comprising magnetic particles over the working electrode.
6. The kit of claim 4 , wherein the reader comprises a processor configured to process signals detected at the working electrode indicative of at least one of a presence, absence, or quantity of a target analyte in the sample.
7. The kit of claim 4 , further comprising the sample collection device.
8. The sample analysis cartridge of claim 1 , wherein the thiolated ethylene glycol comprises ethylene glycol dithiol.
9. The sample analysis cartridge of claim 1 , wherein the working electrode surface is backfilled with a backfiller.
10. The sample analysis cartridge of claim 9 , wherein the backfiller comprises mercaptoundecanoic acid.
11. The sample analysis cartridge of claim 9 , wherein the backfiller comprises mercaptohexanol.
12. The sample analysis cartridge of claim 1 , wherein the working electrode is configured to release electrons to replenish electrons stripped from a substrate by at least one oxidizing enzyme in a quantity that correlates to a quantity of a target analyte in the sample.
13. The sample analysis cartridge of claim 1 , wherein the working electrode surface of the working electrode is gold-plated or comprises gold.
14. The sample analysis cartridge of claim 1 , wherein the working electrode surface of the working electrode comprises a hydrophilic head group.
15. The sample analysis cartridge of claim 1 , wherein the electrochemical sensor further comprises a reference electrode at least partially disposed within the analysis channel.
16. The sample analysis cartridge of claim 1 , wherein the electrochemical sensor further comprises a counter electrode located at least partially disposed within the analysis channel.
17. The sample analysis cartridge of claim 1 , further comprising one or more additional electrochemical sensors at least partially disposed within the analysis channel.
18. The sample analysis cartridge of claim 1 , further comprising a circuit board comprising the electrochemical sensor.
19. The sample analysis cartridge of claim 1 , wherein the circuit board forms a wall of the analysis channel.
20. The sample analysis cartridge of claim 1 , further comprising a piezoelectric transducer configured to emit energy into the reservoir to mix the fluid with the sample and the reagents.