An all-electronic high-throughput detection system can perform multiple detections of one or more analyte in parallel. The detection system is modular, and can be easily integrated with existing microtiter plate technologies, automated test equipments and lab workflows (e.g., sample handling/distribution systems). The detection system includes multiple sensing modules that can perform separate analyte detection. A sensing module includes a platform configured to couple to a sample well. The sensing module also includes a sensor coupled to the platform. The sensing module further includes a first electrode coupled to the platform. The first electrode is configured to electrically connect with the sensor via a feedback circuit. The feedback circuit is configured to provide a feedback signal via the first electrode to a sample received in the sample well, the feedback signal based on a potential of the received sample detected via a second electrode.

TECHNICAL FIELD

The subject matter described herein relates to detection of analytes.

BACKGROUND

A potentiostat is commonly used in electrochemical experiments to probe properties of a physical system, for example, an electrochemical interface between a solid and liquid phase. A potentiostat employs a three electrode system that includes a reference electrode, a working electrode and a counter electrode. The potentiostat operates by maintaining a fixed potential difference between a working electrode and a reference electrode and measuring the current that flows through the electrolyte and across the electrode-electrolyte interface either at the counter electrode or at the working electrode. For example, in bulk electrolysis experiments, a potentiostat measures the total charge that has transferred across an electrochemical interface at a fixed potential difference. The measured charge represents the reduction/oxidation reaction at the interface.

The physical system (e.g., electrode-electrolyte interface) probed by the potentiostat includes one or more systems that exhibit quantum properties, e.g., transport properties associated with mesoscale phenomena (phenomena that lie in between the classical and quantum-mechanical regimes of behavior). Traditional potentiostats are limited in their ability to detect quantum properties at room temperature in electrochemical systems. Additionally, traditional potentiostats are unable to selectively detect quantum signatures of the physical system.

Traditional potentiostats are unable to efficiently perform large-scale detection (e.g., detection of multiple quantum properties of an analyte sample, detection of a quantum property of multiple analyte samples, and the like). Large-scale detection may be desirable for achieving desirable accuracy, scalability and throughput. Therefore, it is desirable to develop a detection system that can detect one or more quantum properties of a plurality of physical system (e.g., electrode-electrolyte interface).

SUMMARY

This application provides for an all-electronic detection system that can allow for quick, efficient and accurate detection of analytes in a sample. The detection system has a high throughput (e.g., information delivered per unit time) that can allow for fast and parallelized detection of a broad spectrum of analyte signatures. High-throughput can be achieved by performing multiple detections of one or more analytes in parallel by using an array of sensing modules. For example, a sample can be distributed in the array of sensing modules, and the portion of the sample in each sensing module can be utilized for detection of one or more analytes. Alternately, the array of sensing modules can detect one or more analytes from multiple samples distributed in the array of sensing module. The sensing modules can be designed to allow for improved analyte detection by enhancing analyte transport in the sample. The detection system can be target agnostic, and does not require special sample preparation. For example, unlike various optical detection systems, the detection system is all-electronic and does not require adding reagents to the sample for detection.

The detection system is modular, and can be easily integrated with existing microtiter plate technologies, automated test equipments and lab workflows (e.g., sample handling/distribution systems). For example, the detection system can be integrated with sample storage systems (e.g., microtiter plates, vials, and the like), which can reduce the need for transferring samples and additional processing steps during detection. Furthermore, due to modular design and integration with off-the-shelf component, the detection system is highly scalable.

In one aspect, a sensing module configured to detect an analyte is provided. The sensing module includes a platform configured to couple to a sample well. The sensor also includes a sensor coupled to the platform. The sensing module further includes a first electrode coupled to the platform. The first electrode is configured to electrically connect with the sensor via a feedback circuit. The feedback circuit is configured to provide a feedback signal via the first electrode to a sample received in the sample well, the feedback signal based on a potential of the received sample detected via a second electrode.

In one aspect, the feedback signal is configured to provide excitation control of redox species in the sample at a third electrode located on the sensor. In another aspect, the feedback circuit is configured to detect a current from the sample via the third electrode. The detected current is indicative of an analyte in the sample. In yet another aspect, the first, second and third electrodes are a counter electrode, a reference electrode and a working electrode, respectively, of a potentiostat. In one aspect, the second electrode is co-located on the sensor. In another aspect, the second electrode is mounted on a wall of the sample well (e.g., when integrated with a flexible substrate). In another aspect, the second electrode is located on a cap configured to removably couple to the sample well. The second electrode includes a lead surrounded by a saturated polymeric jacket. In another aspect, the third electrode includes one or more of gold, platinum, copper, silver, and platinum-iridium. In yet another aspect, the platform includes an electromagnetic shield configured to shield the sensor by attenuating external electromagnetic radiation.

In one aspect, one or more of platform and sample well are configured to shield the sample by attenuating external electromagnetic radiation. In another aspect, the first electrode includes a first end and a second end. The first end is coupled to the platform and the second end is configured to electrically connect with the sample in the sample well. In yet another aspect, the second end includes a surface configured to extend across the sample well. The surface and the platform are substantially parallel to each other. In one aspect, the sample well includes a first, a second and a third well electrode configured to electrically connected to the first electrode, the second electrode and the third electrode, respectively. In another aspect, the sample well includes a first end and a second end. The first well electrode is located at the first end of the sample well and the third well electrode is located at the second end of the sample well.

In one aspect, a detection system configured to detect one or more analytes is provided. The detection system includes a platform configured to receive a sample holder that includes a plurality of sample wells. The detection system also includes a plurality of sensing modules coupled to the platform. A sensing module of the plurality of sensing modules includes a sensor coupled to the platform, and a first electrode coupled to the platform. The first electrode is configured to electrically connect with the sensor via a feedback circuit. The feedback circuit is configured to provide a feedback signal via the first electrode to a sample received in a sample well of the plurality of sample wells. The feedback signal is based on a potential of the received sample detected via a second electrode.

In one aspect, the feedback signal is configured to provide excitation control of redox species in the sample at a third electrode in the sensor. In another aspect, the plurality of sample wells are a plurality of vials. In yet another aspect, the sample holder is a microtiter plate.

In one aspect, the detection system includes a readout system that has a plurality of readout channels. A readout channel of the plurality of readout channels includes the feedback circuit. In another aspect, the readout channel includes an analog-to-digital-converter (ADC) configured to digitize one or more of the detected potential of the received sample and the feedback signal. In yet another aspect, the detection system includes a switching matrix configured to electrically connect the readout channel a first sensing module and a second sensing module of the plurality of sensing modules. A first time duration of electrical contact between the readout channel and the first sensing module is temporally separated from a second time duration of electrical contact between the readout channel and the second sensing module. In another aspect, a contact fixture configured to electrically connect the switching matrix with the platform. In another aspect, the readout system is printed on a circuit board.

In one aspect, a method of detecting analytes is described. The method includes detecting a potential associated with a sample received in a sample well by a first electrode. The method also includes generating a feedback signal by a feedback circuit electrically coupled to the first electrode. The method further includes providing the feedback signal to the sample via a second electrode. The feedback signal is configured to provide excitation control of redox species in the sample at a third electrode. The first, the second and the third electrodes are coupled to a platform configured to receive the sample well.

In one aspect, the feedback circuit is configured to detect a current from the sample via the third electrode, the detected current indicative of an analyte in the sample. In another aspect, the first electrode and the third electrode are located on a sensor. In yet another aspect, the platform includes an electromagnetic shield configured to shield the sensor by attenuating external electromagnetic radiation. In one aspect, the first electrode is located on a cap configured to removably couple to the sample well. In another aspect, the first electrode is mounted on a wall of the sample well.

In one aspect, the second electrode includes a first end and a second end. The first end is coupled to the platform and the second end is configured to electrically connect with the sample in the sample well. In another aspect, the second end includes a surface configured to extend across the sample well, the surface and the platform substantially parallel to each other.

DETAILED DESCRIPTION

An all-electronic high-throughput detection system is described. In one implementation, the detection system can include an array of sensing modules that can couple to a sample holder (e.g., microtiter plate, vial rack, and the like). The array of sensing modules can perform multiple analyte detections in parallel (e.g., simultaneously). A sensing module can couple to a sample well (e.g., a well from the microtiter plate, a vial, and the like) which can hold a sample. The sample can include, for example, redox species and analyte samples. The sensing module can include a vibronic sensor that can establish electrical contact with the sample in the sample well. Once an electrical contact has been established, the vibronic senor can detect one or more analytes in the sample.

The array of sensing modules can make multiple detections in parallel. For example, the detection system can detect analytes in multiple samples (e.g., the multiple samples placed in multiple sample wells). This results in a higher through-put compared to a system that performs detection on one sample at a time. Multiple detection in parallel can also improve the accuracy of analyte detection. For example, a sample can be distributed over multiple sample wells (e.g., multiple vials, multiple wells of a microtiter plate) and detected by multiple sensing modules in the array. This can enable quick and large-scale data collection that can provide statistically large population of data for accurate detection. Accurate detection may be desirable, for example, in the development of complex panel assays for food safety or clinical applications.

The vibronic sensor of a sensing module can be a potentiostat with a high-gain low-noise feedback system as described in Provisional Application No. 62/328,798 and PCT Application Serial No. PCT/US2017/29854, the contents of which are incorporated herein by reference in its entirety. Other vibronic sensor architectures have been described in U.S. Pat. No. 9,285,336, U.S. application Ser. No. 14/455,205, and Provisional Application No. 62/523,729 and U.S. application Ser. No. 16/016,468, which are incorporated herein by reference in their entirety.

The vibronic sensor can include electrodes (e.g., reference electrodes, counter electrodes and working electrodes) and a high-gain low-noise feedback circuit. The vibronic sensor can detect electrical properties of the sample (e.g., potential) via the reference electrode, and the feedback circuit can provide a feedback signal (e.g., feedback current) via the counter electrode. The feedback signal can suppress dissipative effects of thermodynamic environment on the interaction between analytes and vibronic states of redox species in the sample. This can allow for room temperature detection of signatures of analytes (e.g., analyte depenent currents) at the working electrode.

The vibronic sensor can be modular that makes it compact and easily integrable with the existing devices and measurement techniques. For example, the reference electrode, counter electrodes, working electrodes and the feedback circuit can form separate modules which can be electrically connected to form the vibronic sensor. In some implementations, parts of the vibronic sensors can be coupled to a sample well (e.g., microtiter well, vial, and the like) designed to hold the sample. In some implementations, the reference and working electrodes can be coupled together to form a chip scale sensor. In other implementations, the chip scale sensor only includes the working electrode. The chip scale sensor can be designed to couple/decouple with a holder in the sensing module by a mechanical clip, low temperature adhesive, UV curable adhesive, and the like. The sensing module can include an electromagnetic shield to protect the portions of the vibronic sensor (e.g., chip scale sensor, counter electrode, working electrode, reference electrode, and the like). The electromagnetic shield can include, for example, a metallic cage-like structure that can surround portions of the vibronic sensor and attenuate ambient electromagnetic radiation (e.g., radiation emanating from readout circuitry and the ambient surrounding).

The modular vibronic sensor design can have a separate counter electrode with a geometry and an orientation that allows for fast and accurate detection of analytes. For example, it can be designed to have a large contact area with the sample. A portion of the counter electrode can be a flat surface that can be immersed in the sample. The large contact area can increase the flux of charge carrying redox species from the counter electrode to the working electrode (e.g., located on the chip scale sensor) and vice-versa. The flux of redox species can drive species in the sample (e.g., analytes, redox species) towards the working electrode in the chip scale sensor. This can improve the accuracy of analyte signature detection at the working electrode (e.g., by resulting in a stronger detection signal). The flux of redox species can also be varied by varying the distance between the counter electrode and the working electrode.

In some implementations, feedback circuits associated with the various sensing modules can be included in a readout system. The readout system can be implemented, for example, as a printed circuit board. Details of a readout circuit in the readout system is described in Provisional Application No. 62/328,798 and PCT Application Serial No. PCT/US2017/29854, which are incorporated herein by reference in its entirety. The readout system can include multiple readout channels. A readout channel can include sensing and feedback circuitry of the sensing modules. The readout channel can detect potential of a sample in the sample well via the reference electrode, and based on the detected potential provide a feedback signal (e.g., current signal) via the counter electrode. The readout channel can detect a current signal from the working electrode that can contain signatures of analytes in the sample. Furthermore, the readout channel can digitize the data of detected sample properties (e.g., by an analog-to-digital converter [ADC]), and can provide the digitized data to an external computing device.

In one implementation, the readout system can be integrated with the detection system. For example, readout channel can be fabricated as an application specific integrated circuit. In other implementations the readout system can be included in a handheld device that can be electrically connected to the detection system (e.g., at the time of detection). The readout system can communicate with a computing device, either wirelessly or via a serial bus connection. For example, a readout channel integrated/fabricated with the chip scale sensor can wirelessly transmit information related to sample detection, feedback system, and the like. This can make the sensing module that includes the aforementioned chip scale sensor an independent detection system capable of detecting analytes.

The readout system can be electrically connected to the sensing modules of the detection system via a contact fixture. The contact fixture can include conductive pins that are spatially distributed to contact the sensing modules (e.g., vibronic sensor in the sensing module). The spatial distribution of the conductive pins can be based on a predetermined geometry of the sensing modules (e.g., spatial location of working electrode, reference electrode and reference electrode in the vibronic sensor module).

In conjunction with the contact fixture, the electrical connection between the readout system and the sensing module can be established by a switching matrix. The switching matrix can allow a readout channel in the readout system to control the operation (e.g., provide feedback signal, detect sample potential, and the like) of multiple sensing modules. The switching matrix can establish a time-sharing scheme where the readout channel sequentially controls multiple sensing modules. In one implementation, the switching matrix can designate a predetermined operation time during which a read out channel interacts with a sensing module. After the predetermined operation time has elapsed, the read out channel interacts with another sensing module. The switching matrix can be programmed to dynamically change the operation time. For example, the switching matrix can allow for a longer operation time for samples with anaytes that take longer to detect. Alternately, if the threshold accuracy of detection changes, the operation time can accordingly change (e.g., longer operation time for greater accuracy).

One or more samples can be deposited in the sample storage (e.g., wells of a microtiter plate, vials in a vial rack) by a liquid handler. The liquid handler can determine the volume of sample to be deposited in a sample well of the sample storage. For example, in some implementations the volume of sample in a sample well should be greater than a threshold value in order to establish electrical connection between vibronic sensing module (e.g., working electrode, reference electrode, counter electrode, and the like) and the sample. In some implementations, the liquid handler can track the sample delivery process (e.g., properties of samples deposited in the sample storage, time of delivery, sample volume, and the like). The liquid handler can also identify the sample storage. For example, the liquid handler can include a camera (e.g., attached to a sensing system inFIG. 11) that can identify an identifier (e.g., QR code, barcode, etc.) associated with the sample storage. The liquid handler can include robotic interfaces that can pipette liquid into the sample storage and can be distinct from the integrated socket.

The volume ratio of redox species and analyte sample has a desired predetermined value that can be maintained by the liquid handling procedures or apparatus. For example, the liquid handler can add a volume of analyte sample in the sample well followed by a volume of redox species (or vice versa). The ratio of the volumes can be selected to prevent undersired reactions at the chip-scale sensor-sample interface (e.g., prevent/reduce excessive accumulation of species at the working electrode that adversely affect the detection process). In one implementation, the volume of the electrolyte containing the redox species can range from about 0.5 milliliter (mL) to about 1 mL, and the volume of the sample can range from about 1 microliter to 100 microliter.

Implementations of analyte detection system.

FIG. 1Aillustrates a cross section of a sensing module100coupled to a microtiter well150(a sample well). The sensing module100includes a platform110that can couple to a chip scale sensor112and an electrode114. For example, the platform110can include holders120and122that are designed to receive/mate with chip scale sensor112and electrode114respectively. The holders120and122can include an electromagnetic shield to protect the chip scale sensor112and electrode114from external electromagnetic radiation. The platform110can also couple with the microtiter well150to enclose a volume160that can hold a sample (e.g., electrochemical solution with redox species and analytes). The sample can be introduced into the volume160through the inlet124in the platform110. Alternately or additionally, sample can be placed in the microtiter well before the platform110is coupled to the microtiter well150.

A first end116of the electrode114is coupled to the platform110via the holder122. A second end118of the electrode114can extend across a portion of the volume160. For example, the second end118can be a flat surface that extends parallel to the platform110. Large surface area of the second end118can establish a robust and/or uniform electrical connection between the first electrode and the sample in volume160.

The chip scale sensor112and electrode114are configured to make contact with the sample in the volume160. For example, platform110can include an orifice where the chip scale sensor is received. A surface of the chip scale sensor112proximal to the platform110can contact the sample in the volume160through the orifice. The proximal surface of the chip scale sensor112can include multiple electrodes (e.g., working electrode, reference electrode, and the like) that can contact the sample. The second end118of the electrode114can also contact the sample in the volume160. For example, the second end118can be submerged in the sample contained in the volume160.

The chip scale sensor112and the electrode114can be electrically connected, for example, via a feedback circuit (e.g., feedback circuit in a readout channel) and/or the sample in the microtiter well150. The chip scale sensor can include conductive pins that can establish electrical contact with the feedback circuit (e.g., feedback circuit in the readout channel). The conductive pins can be located on a distal surface of the chip scale sensor which is located on the opposite side of the proximal surface of the chip scale sensor. The first end116of the electrode114can be in electrical contact with the feedback system. The chip scale sensor112and the electrode114can be connected to a contact fixture (e.g., contact fixture described above). As described later, in some implementations, the chip scale sensor112and the first electrode can be electrically connected to a readout circuit (e.g., located in the readout channel) that can include the sensing and feedback systems, via a switching matrix.

The electrodes on the chip scale sensor112, the first electrode114and the feedback system can constitute a potentiostatic apparatus that can detect one or more analyte through detection of mesoscale/quantum properties as described in Provisional Application No. 62/328,798 and PCT Application Serial No. PCT/US2017/29854, which are incorporated herein by reference in its entirety. The potentiostatic apparatus (also referred to as “vibronic sensor” or “vibronic sensor module”) can detect analytes in a sample by detecting the effect of analytes on vibronic states of redox species in the sample during an electron transition process.

The first electrode114can act as a counter electrode of the vibronic sensor, and a second and third electrode on the proximal surface of the chip scale sensor112can act as the reference electrode and working electrode, respectively, of the vibronic sensor. The feedback system can have low-noise (e.g., based on cascaded high-gain amplifier design), and can detect a potential associated with the sample in the volume160via the reference electrode in chip scale sensor112. Based on the detected potential, the feedback system can provide a feedback signal (e.g., feedback current) to the sample via the first electrode.

The redox species in the sample can exchange electrons at the counter electrode and the working electrode (e.g., gain/lose one or more electrons). Analytes located in proximity to the working electrode can affect the electron exchange process at the working electrode by perturbing the vibronic states of the redox species. As a result, the current generated by the exchange of electrons at the working electrode can include signatures of the analytes. Analytes can be determined by detecting the current at the working electrode, and analyzing the detected current (e.g., by comparing the detected current with analyte characteristic information in a database).

Properties of the working electrode can be determined based on various design consideration that is discussed in detail in Provisional Application No. 62/523,729 and U.S. application Ser. No. 16/016,468, which are incorporated herein by reference in their entirety. The working electrode can include a nano-scale electrochemical interface that can allow for selective detection of quantum signatures in a charge transfer processes at the electrochemical interface.

FIG. 1Billustrates a cross section of an exploded view of the sensing module100and sample well150inFIG. 1A. After a sample with analytes is deposited in the sample well150(e.g., by the liquid handler), the sensing module100can be suspended into the sample well150such that the distal end of the counter electrode114is in electrical contact with the sample. In other implementations, the sample can be introduced in the sample well via an inlet (e.g., inlet124,125) in the platform110. If the volume of the sample exceeds the volume of sample well150, the excess sample/trapped bubbles can flow out of the inlets124,125. The inlets124,125can have microfluidic features to induce transport of sample species in the sample well150using surface tension and capillary effects.FIG. 1Cillustrates an exploded perspective view of the sensing module inFIG. 1A.

FIG. 2illustrates a schematic rendering of transport of species in the sample well-sensing module system ofFIG. 1A. The sample well150is designed to facilitate robust electrical contact between vibronic sensor (e.g., chip scale sensor112, counter electrode114) and the enclosed sample. For example, volume of the sample (“sample volume”) can be determined such that when added in the sample well150, chip scale sensor112and counter electrode114establish electrical contact with the sample. The location and size of the counter electrode114can determine the rate of transport of species in the sample (e.g., redox species, analytes, and the like) between the counter electrode114and the chip scale sensor112. For example, the distance between the counter electrode114and the chip scale sensor112can determine a transport zone202of the recirculating flow of the redox species due to the oxidation-reduction reactions occurring at the working electrode (located in the chip scale sensor112) and counter electrode114(also referred to as “transport cone”). The transport of the sample can occur in the transport zone202. After a volume of sample reaches the chip scale sensor112, it can recirculate back towards the counter electrode114(e.g., along a sample flow channel204). The electrochemical potential gradient set up between the counter and working electrodes can determine the nature of the flux of species in the sample well volume. As the electrochemical potential gradient/flux of the species increases, the travel time of the specie between the counter electrode114and the chip scale sensor112can decrease. This can decrease the time needed for detecting the sample.

The counter electrode114can be much larger than the chip scale sensor112to ensure that the flux of the redox species covers the entire cross-sectional area of the sample volume. The redox specie can drag the analyte as it moves from the counter electrode114to the chip scale sensor112. Because the detection of analytes occurs at the chip scale sensor112, it can be desirable to increase the flux of the redox species. It can also be desirable to increase the volume of the transport zone so that more analytes are dragged by the diffusion of the redox species (e.g., by viscous forces from the solvent). The volume of the transport zone202can be increased by increasing the distance between the chip scale sensor112and the counter electrode114and/or the size of the counter electrode114.

FIG. 3Aillustrates a perspective view of a detection system300that includes an array of sensing modules attached to a platform310. The detection system300can couple with a microtiter plate350. For example, the sensing modules of the detection system300can couple with the wells of the microtiter plate350. The various sensing modules can perform analyte detection of multiple samples in the microtiter plate350in parallel (e.g., simultaneously).FIG. 3Billustrates an exploded view of the sensor array and microtiter plate illustrated inFIG. 3A.

FIG. 4illustrates a schematic view of an implementation of a detection system400that can detect analytes in samples placed in the wells of the microtitier plate450. The image of the detection system400has been exploded to illustrate the platform410, the contact fixture440and an interface board460. The platform410can include multiple sensing modules. A sensing module can include chip scale sensor412and inlets424. The contact fixture440can be electrically connected to the platform410by multiple testing probes/conducting pins411a,b. The conducting pins can be geometrically arranged to make electrical contact with the chip scale sensors412(e.g., working electrode and reference electrode in the chip scale sensor) and counter electrodes (not shown). The contact fixture440can be in electrical contact with the interface board460. The interface board460can include the readout system. The contact fixture440can establish electrical connection between the readout channels of the readout system and sensing modules of the detection system400. After an electrical contact has been established between a readout channel (which includes sensing and feedback circuits) and a sensing module (e.g., counter electrode, working electrode, reference electrode of the sensing module), detection of analytes in the microtiter plate450can be performed.

In some implementations, the detection system400can include a switching matrix. The switching matrix can be incorporated in the interface board460, contact fixture440or can be included in a separate module. The switching matrix can serve as an interface between the interface board460and the contact fixture440. As described before, the switching matrix can be establish electrical connection between a readout channel and multiple sensing modules (e.g., sequentially in time). For example, eight readout channels can drive eight sensing modules in parallel. If the detection system includes ninety six sensing modules (e.g., for a microtiter plate having ninety six wells), and eight sensing modules can be driven in parallel, the detection system can perform analyte detection in all ninety six sensing modules in twelve steps. If the expected time of detection of each step is 10 minutes, the total detection time will be about two hours.

The interface board460also includes pins490through which communication with an external computing device can be established. In some implementations, the interface board460can wirelessly communicate with an external device (e.g., by short-range wireless communication methods like WiFi, Bluetooth, and the like). The interface board460can digitize sensing/feedback information of the various sensing modules and upload the information to a database in the computing device.

FIG. 5illustrates a schematic view of a detection system500in communication with a computing device550as described above. The detection system500can include a plurality of microtiter plates502(e.g., microtitier plate450), a platform504(e.g., platform410), a contact fixture506(e.g., contact fixture440), a switching matrix508and a readout system510.

In some implementations, the interface board460, contact fixture440and switching matrix can be integrated to form a testing module. A testing module can be designed for a known detection system, and can be available off the shelf. During detection, a user can assemble the testing module with the corresponding detection system. Such a configuration improves the modularity of high-throughput analyte detection process.

FIGS. 6-10illustrate another implementation of an analyte detection system.FIG. 6illustrates a detection system600that can receive multiple vials in a vial rack650. A vial602can include a vial well610that receive a sample for analyte detection. The inner wall of the vial well610can include/couple to multiple electrodes that can electrically contact the sample in the vial well610. The vial602can include a base module620(seeFIG. 7A) located at the base of the vial well610. The base module620can be monolithically fabricated with the vial well610(e.g., by moulding) at a distal end603a. The vial well610can include a first electrode614a(e.g., located at a proximal end603bof the vial602). The base module620can include a second electrode616a. The vial well610can include a third electrode618a. The first, second and third electrodes can extend to the outer surface of the vial602and can electrically couple to external electrodes/power connections. (e.g., second electrode616acan be electrically connected to a flex connector630located on the base module620). The vial602can be coupled with a sensing module622of the detection system600. When the vial602is coupled with the sensing module622(e.g., when the vial is directed into the vial rack650), portions of the vial electrodes can come in electrical contact with electrodes of the sensing module622. For example, counter electrode614bof the sensing module622can establish electrical contact with the first electrode614aof the vial602, reference electrode618bof the sensing module622can establish electrical contact with the third electrode618aof the vial602, and working electrode616bof the sensing module622can establish electrical contact with the second electrode616aof the vial602. After an electrical contact has been established between the electrodes of the vial and the electrodes of the sensing module622(e.g.,614b,616band618b), electrodes614a,616aand618acan operate as counter, working and reference electrodes, respectively. The sensing module622can include a low-noise feedback system (e.g., low-noise feedback system described in Provisional Application No. 62/328,798) that can electrically couple to the counter electrode614b, working electrode616band reference electrode618b. The low-noise feedback system can detect analytes in the sample received by the vial well610.

In some implementations, electrode618acan be replaced by an electrode system (not shown) mounted on the inner wall of the vial602. The electrode system can include an electrode (e.g., a screen printed Ag/AgCl/KCl polymer jacketed electrode) integrated on a flex and mounted on the inner wall602. The electrode system can conform to the shape of the inner wall of the vial602. For example, the electrode system can have a shape of a sheet that can couple to the inner wall of the vial602.

FIG. 7Aillustrates the base module620of the vial602. The detection system600can includes multiple sensing modules (e.g., array of sensing modules). The vial602can be coupled (e.g., mechanically attached) with the sensing module622. For example, an attachment mechanism such as a clip or a socket can engage the vial602with the sensing module622when the latter is pushed against the sensing module622. The base module620can include access port632that can, for example, allow the sample in the vial602to contact the working electrode. The flex connectors630can be designed to mate with electrode616bof the sensing module622.

FIG. 7Billustrates another exemplary implementation of a vial. The vial702includes a cap704that can removably couple to a vial well710. The vial well710can receive a sample for analyte detection. The inner wall of the vial well710can include/couple to a first electrode714a, and the cap704can include/couple to a second electrode718a. For example, the first and second electrodes714aand718acan be located at a proximal end703bof the vial702. The first electrode714aand the second electrode718bcan electrically couple with the sample in the vial well710. The vial702can include a base module (not shown) at a distal end703aof the vial702. The vial well710can include a third electrode (not shown) at the distal end703aof the vial702.

The vial702can be coupled with a sensing module of a detection system. When the vial702is coupled with the sensing module, portions of the first electrode714a, second electrode718aand the third electrode of the vial702can come in electrical contact with electrodes of the sensing module. For example, the first electrode714a, the second electrode718aand the third electrode can couple to couple to a counter electrode, a reference electrode and a working electrode, respectively, of the sensing module. After an electrical contact has been established between the electrodes of the vial702and the electrodes of the sensing module, electrodes714a, and718acan operate as counter, and reference electrodes, respectively. The third electrode can operate as a working electrode.

FIG. 7Cis a schematic illustration of the cap704. The cap704includes a base705that can mechanically couple with the vial well710(e.g., at distal end703bof the vial well710). The cap704can also include the second electrode718bthat can establish electrical contact with the sample in the vial well710. In some implementations, the second electrode718bcan include of a pin assembly (e.g., composite heterogeneous pin assembly made of one or more of Ag plating, AgCl, 3M halogenated salt like KCl, NaCl, etc.) surrounded by a saturated polymeric jacket. The pin assembly can be integrated into the base705.FIG. 7Dillustrates a perspective view of exemplary implementations of the cap704.

The detector600can include the contact fixture, the switching matrix and the readout system. For example, they can be located below the array of sensing modules. As illustrated inFIG. 8, the detection system600can communicate with an external computing device via serial bus690or via short-range wireless communication. The sensing module620can act as an independent detection system that can detect an analyte and transfer sensing/feedback information to the external computing device.

Method of Use

In one implementation, a sample can be placed in one or more sample wells (e.g., microtiter well, vial, and the like) of an analyte detection system including an array of sensing modules (e.g., detection system400,600and the like). The sample includes analyte samples and electrolyte (having redox species). Analyte samples (e.g., blood) include the analytes to be detected (e.g., DNA, RNA oligomers, peptide fragments, proteins, glycans, polysaccharides, metabolites, pathogenic organisms and the like). The electrolyte (e.g., an aqueous solvent, an organic solvent, and the like) can include redox species (e.g., ferro-/ferricyanide couple, ferrocenium ion and ruthenium hexaamine complex, potassium hexacyanoferrate (ii)/(iii), and the like). In exemplary samples, the concentration of analyte in the sample can range from 1 pg/ml to 1 mg/dl.

The sample can be placed in the sample wells by hand or by a liquid handler.FIG. 9illustrates an exemplary liquid handler900for transferring samples into the vials of a detection system. The liquid handler900can transfer one or more electrolytes and analyte samples into the sample well (e.g., from a microtiter plate910to the vials of the detection system).

The detection system detects a potential associated with the sample (e.g., via the reference electrode) and the feedback circuit (e.g., feedback circuit in the readout channel) provides a feedback control signal (e.g., via the counter electrode) to the sample. The feedback control signal can suppress voltage noise of the sample. The voltage noise can be representative of energy fluctuations in the sample (e.g., in the vicinity of an interface between the electrolyte and a working electrode). This can result in efficient resonant charge transfer between, for example, the electrolyte-dissolved redox species and the working electrode (e.g., charge transfer between discrete electronic energy levels of vibration-dressed electronic states in the redox species and energy levels in the working electrode). The feedback control signal can limit the multiple scattering contributions from the environment which can result in resonant charge transfer.

An analyte in the sample can be detected from working electrode current indicative of the analyte dependent resonant charge transfer process at the working electrode. The feedback circuit can detect the current at the working electrode and digitize the feedback current information (e.g., using an analog to digital converter). The feedback current information can be compared with information related to the effects of various analytes on charge transfer process (e.g., information stored in a database).

FIG. 10illustrates a point-of-care detection system1000. The point-of-care detection system can have a sensing module that can couple with a vial1010(e.g., vial602), for example, by a mechanical socket. The mechanical socket can ensure that electrical connection between the electrodes of the vial and the electrodes of the sensing module is robustly established. The detection system1000can include a contact fixture and a readout channel. Because the detection system1000has a single sensing module, the detection system1000may not include a switching matrix. The detection system1000can communicate with a readout and computing device1020(e.g., via a data pin, by short-range wireless communication). For example, the detection system1000can be plugged into the computing device1020.

FIG. 11illustrates an exemplary stand-alone detection system1100. The stand-alone detection system1100can include a sensing system1102, a communication system1104and a power delivery system1106. The sensing system1102can be configured to couple to a vial1110. In some implementations, the vial1110can be mechanically integrated with the sensing system1102. In some implementations, the vial1110can be slid into the sensing system1102. The vial1110can include electrodes that can couple to a sample that can be received by the vial1110. For example, the electrodes of the vial1110can operate as counter electrode, working electrode and reference electrode (e.g., as described in reference to vials602,702, etc.).

The sensing system1102can include a low-noise feedback system (e.g., low-noise feedback system described in Provisional Application No. 62/328,798 and PCT Application Serial No. PCT/US2017/29854, which are incorporated herein by reference in its entirety) that can detect analytes in the sample received by the vial1110. The feedback system can electrically couple to electrodes of the vial1110. The sensing system1102can include a camera that can be used to track individual vial units (e.g., for quality control purposes). For example, the camera can be an optical code reader that can detect a bar code (e.g., bar code on the vial1110). The bar code can be associated with the sample in the vial1110, and the detected bar code can be indicative of the sample and/or individual vial unit in the vial1110.

The communication system1104can be in communication with the sensing system. The communication system1104can receive analyte data detected by the sensing system1102, bar-code data detected by the camera (seeFIG. 13), etc. The communication system1104can include a microcontroller unit that can transmit data (e.g., analyte data, bar-code data, etc.) to an authorized computing device (e.g., computer, tablet, cellphone, etc.), a server, etc. In some implementations, the data can be transmitted to an intermediate gateway (or a user interface in the authorized computing device) and/or an external server (e.g., a cloud). The computing device/server can verify data received from the communication system1104, and can perform additional data analysis.

The data can be transmitted wirelessly (e.g., via WiFi, Bluetooth, and the like), and/or via serial ports (e.g., USB) (e.g., between the communication system1104and the intermediate gateway, between intermediate gateway and a cloud server, etc.) An authorized user can access the transmitted data via a secured connection. A network of multiple stand-alone detection systems1100(e.g., network of 96, 384, etc., detection systems) can perform multiple detections (e.g., simultaneously). Such a network can result in a high throughput analyte detection system.

The power delivery system1106can include a power source (e.g., a removable battery) to provide energy to the sensing system1102, communication system1104, etc. The stand-alone detection system1100can be modular. For example, the sensing system1102, the communication system1104and the power delivery system1106can be assembled together to form the detection system1100and can be disassembled (e.g., after analyte detection).

FIG. 12illustrates coupling between the vial1110and the sensing system1102. Portion of the sensing system at a distal end1112of the vial1110can include a feedback circuit and/or a camera.FIG. 13illustrates an exemplary camera that can be integrated into the sensing system1112(or in the distal end of the vial1110).

Working Example

A sensing module with a feedback circuit detects biomolecular analytes within a complex clinical sample like whole blood in an electrolyte containing the potassium ferri-/ferro-cyanide redox couple. The concentration of the analyte in the electrolyte ranges from 1 pg/ml (picogram/milliliter) to 1 mg/dl (milligram/deciliter). The sensing module includes a counter electrode, a reference electrode and a working electrode that are in electrical contact with the electrolyte. The counter, reference and working electrodes are made of metals (e.g., gold, platinum, platinum-iridium, silver, silver/silver-chloride). The sensing module detects the potential of the redox active species in the electrolyte at the reference electrode, and based on the detected potential, provides a low-noise high gain feedback current signal to the electrolyte via the counter electrode. The charge in the current signal is carried between the counter electrode and the working electrode by phosphate and cyanide anions and potassium cations.

Choice of metals for the electrodes leads to electrochemical stability for potentials ranging from −1 volt to 1 volt. For example, gold and platinum electrodes enable thin film chemistry functionalization, like a self assembled film comprising 1-propanethiol. The portion of the counter electrode immersed in the sample has an area of about 0.5 cm2to about 1 cm2. The working electrode has an area of about 2500 nm2. The distance between the aforementioned portion of the counter electrode and a working electrode in the chip scale sensor ranges from about 0.5 cm to about 1 cm. Volume of the redox species ranges from 0.5 ml to 1 ml. Volume of the analyte sample (containing analyte to be detected) ranges from 1 μl (microleter) to 10 μl. The horizontal extent of the sensing module can be approximately 9 mm and the vertical extent of the sample well can be approximately 15 mm.