University of California

Leland Stanford Junior University

Other

Drew A Hall

Shan X Wang

Kyunglok Kim

Richard Samuel Gaster

Chung-Lun Hsu

Alexander Chuan Sun

Patrick Mercier

Sebastian J Osterfeld

Eliah Aronoff-Spencer

Po-Han Wang

Yunting Zhao

Haowei Jiang

Saurabh Kulkarni

Richard Gaster

Disclosed are biosensor devices, systems, and methods for point-of-care applications. In some aspects, a biosensor system includes a biosensor chip device to measure impedance at an electrode-electrolyte interface, which includes an electrochemical sensor comprising a first electrode including a functionalization layer exposing a molecular binding site to bind a target molecule for detection and a second electrode that does not include the binding site, and an electronic circuit unit corresponding to each electrode of the electrochemical sensor including a transimpedance amplifier, a phase detector to determine a relative phase shift in the detected electrical signal caused by an impedance change from a binding event of the target molecule at the molecular binding site, and a time-to-digital converter to quantize and average phase data points in time to remove uncorrelated noise from the detected electrical signal; and a signal generator to produce an electrical excitation signal applied across the electrode-electrolyte interface.

Electrochemical biosensor array devices, systems, and methods for point-of-care detection

An implantable biosensor may be placed subcutaneously to monitor the concentration of an analyte in a body fluid. The biosensor may include an electrochemical cell and an antenna. The components of the biosensor, including the electrochemical cell and the antenna, may be disposed on a same substrate. The electrochemical cell may include multiple electrodes for performing electrochemical measurements that include a first measurement of the analyte concentration in the body fluid, a second measurement of a background interference present in the body fluid, and a third measurement of a pH level within the body fluid. The antenna may receive, from a transceiver, radio frequency (RF) waves for wirelessly powering the implantable biosensor. The antenna may further transmit, back to the transceiver, a backscatter signal encoding a result of the electrochemical measurements.

Implantable biosensor

In one aspect, an analog-to-digital converter circuit includes a transimpedance amplifier including a feedback capacitor electrically connected between an inverting or a non-inverting input of the transimpedance amplifier and an output of the transimpedance amplifier. The circuit includes an hourglass switch electrically connected on a first side to a first input and a second input, and electrically connected on a second side to the non-inverting input and the inverting input. A fine input current to the transimpedance amplifier is received at the first and second inputs. In a first mode, the hourglass switch electrically connects the first input to the non-inverting input and the second input to the inverting input, and in a second mode, the hourglass switch electrically connects the second input to the non-inverting input and the first input to the inverting input.

Wide dynamic range current measurement front-end

Some embodiments relate to a reconfigurable biosensor adapted for performing tests in a plurality of modes or a smartphone or wearable device comprising the reconfigurable biosensor.

Reconfigurable, multi-technique electrochemical portable biosensor

A low-power wake-up receiver. The receiver includes a transformer/filter resonating at a pre-selected frequency to realize passive RF voltage gain. A pseudo-balun envelope detector is coupled to an output of the transformer filter. A comparator or other quantizer is coupled to an output of the active pseudo-balun envelope detector (ED) for comparing the ED output to a comparison threshold voltage. The pseudo-balun envelop detector can be an active detector. The pseudo-balun detector can also be a passive detector.

Low power wake-up receiver

Correlated double sampling (CDS) for magnetoresistive (MR) sensors is provided. Here the MR sensor output is sampled at two closely spaced times. The first sample is MR signal+baseline+noise and is sampled when the modulated magnetic field is non-zero. The second sample is baseline+noise only because it is sampled when the modulated magnetic field is zero. The difference between the first and second samples will have significantly reduced low frequency noise and baseline cancellation. Modulation of the electrical bias provided to the MR sensor can be used to provide a baseline signal for temperature compensation. In a second aspect, we provide MR sensor arrays having input and output multiplexing and demultiplexing for row and column line selection, in combination with a per-sensor switch to prevent noise accumulation and bandwidth reduction from idle MR sensors.

Correlated double sampling for noise reduction in magnetoresistive sensors and sensor arrays

Sensor assay methods for detecting the presence of an analyte in a sample are provided. Aspects of the methods include providing a sensor, e.g., a proximity sensor, in contact with an assay composition that includes a sample and a proximity label. Next, a capture probe configured to bind to the proximity label and the analyte is introduced into the assay composition to produce a labeled analyte. Following capture probe introduction, a signal is obtained from the sensor to detect the presence of the labeled analyte in the sample. Also provided are sensor devices, including hand-held devices, and kits that find use in practicing the subject methods.

Methods and devices for detecting the presence of an analyte in a sample

Double modulation of a magnetoresistive sensor entails modulating both an excitation (e.g., voltage or current) applied to the sensor and a tickling magnetic field applied to the sensor. The excitation and magnetic field are modulated at different frequencies fand f, respectively. As a result of the double modulation, the sensor output spectrum includes a carrier tone (CT) at frequency fand side tones (STs) at frequencies f&#xb1;f. A baseline relation between CT amplitude and ST amplitude is determined (e.g., by measuring CT and ST amplitude while drift occurs in the absence of a sample). During sensor operation, raw ST measurements are corrected using corresponding raw CT measurements to provide corrected ST measurements as the sensor output.

Growing community of inventors

La Jolla, CA, United States of America

Drew A Hall