Methods for detecting polynucleotides, especially the DNA replicated from samples obtained from subjects infected with pathogenic viruses such as human immunodeficiency virus, by detecting electromagnetic signals (“EMS”) emitted by such polynucleotides, and methods for improving the sensitivity of the polymerase chain reaction (“PCR”).

Systems and methods for processing sensor data and self-calibration are provided. In some embodiments, systems and methods are provided which are capable of calibrating a continuous analyte sensor based on an initial sensitivity, and then continuously performing self-calibration without using, or with reduced use of, reference measurements. In certain embodiments, a sensitivity of the analyte sensor is determined by applying an estimative algorithm that is a function of certain parameters. Also described herein are systems and methods for determining a property of an analyte sensor using a stimulus signal. The sensor property can be used to compensate sensor data for sensitivity drift, or determine another property associated with the sensor, such as temperature, sensor membrane damage, moisture ingress in sensor electronics, and scaling factors.

Provided is a method for detecting a test substance. In this method, metal is deposited or a complex containing a test substance and a metal particle is immobilized on a working electrode on an electrode substrate including the working electrode and a counter electrode. An oxidation potential is applied to the working electrode to generate metal ions, then a reduction potential is applied to a portion having an area smaller than an area of the portion to which an oxidation potential is applied in the working electrode to deposit metal on the surface of the portion to which the reduction potential is applied, and current, voltage or charge caused by the metal deposited is measured to detect metal ions or a test substance.

Provided is a method for detecting a test substance. In this method, metal is deposited or a complex containing a test substance and a metal particle is immobilized on a working electrode on an electrode substrate including the working electrode and a counter electrode. An oxidation potential is applied to the working electrode to generate metal ions, then a reduction potential is applied to a portion having an area smaller than an area of the portion to which an oxidation potential is applied in the working electrode to deposit metal on the surface of the portion to which the reduction potential is applied, and current, voltage or charge caused by the metal deposited is measured to detect metal ions or a test substance.

Disclosed are methods and devices for detection of ion migration and binding, utilizing a nanopipette adapted for use in an electrochemical sensing circuit. The nanopipette may be functionalized on its interior bore with metal chelators for binding and sensing metal ions or other specific binding molecules such as boronic acid for binding and sensing glucose. Such a functionalized nanopipette is comprised in an electrical sensor that detects when the nanopipette selectively and reversibly binds ions or small molecules. Also disclosed is a nanoreactor, comprising a nanopipette, for controlling precipitation in aqueous solutions by voltage-directed ion migration, wherein ions may be directed out of the interior bore by a repulsing charge in the bore.

A computer-implemented method for interpreting an electrochemical response, comprises the steps of: (a) providing an electrochemical response that is baseline-corrected; (b) identifying in the electrochemical response one or more peaks that exceed a predetermined height threshold and a predetermined prominence threshold, each identified peak having a peak position; (c) providing a predetermined peak position range for each of a plurality of analytes; and (d) attributing one or more of the analytes to the peaks identified in step b, by, for each peak, associating the peak with an analyte when the peak position falls within the predetermined peak position range for the analyte.

Provided is a method for sensing methyl salicylate, which is a plant hormone released when a plant is infected with a disease in cultivation of plants including agricultural crops, and thereby provided a method for early in-situ detection of disease infection in a plant. With the present embodiment, disease infection in a plant can be detected at an early stage by utilizing a rare earth compound that selectively recognizes and forms a complex with methyl salicylate, which is a plant hormone released when a plant is infected by a pathogen, as a receptor for sensing, and by utilizing a fluorescence emission phenomenon and a change in electrochemical behavior after the reaction with methyl salicylate.

A method for determining a membrane property of an analyte sensor that has at least two measurement electrodes and at least one of the measurement electrodes has a membrane having the membrane property. The method includes generating a fast-transient voltage signal and applying the fast-transient voltage signal to the measurement electrodes. A response signal is measured, and the membrane property is determined by evaluating the response signal.

A method for determining a membrane property of an analyte sensor that has at least two measurement electrodes and at least one of the measurement electrodes has a membrane having the membrane property. The method includes generating a fast-transient voltage signal and applying the fast-transient voltage signal to the measurement electrodes. A response signal is measured, and the membrane property is determined by evaluating the response signal.

A method of preparing a working electrode on a sensor substrate is disclosed. A sensor substrate is provided and has a first side with at least one conductive trace. A layer of sensing material is applied onto the first side and covers at least a portion of the at least one conductive trace. The sensing material is irradiated with a laser beam to partially remove the layer of the sensing material while preserving a portion of the sensing material covering the at least one conductive trace, resulting in a working electrode on the sensor substrate. A membrane layer is applied that at least partially covers the working electrode. The membrane layer includes a cross-linker that cross-links at least a part of the sensing material. A diffusion step is performed during which the cross-linker in the membrane layer at least partially diffuses into the sensing material.