A fully or partially implantable analyte sensor for continuously monitoring analyte concentration in a body fluid has a substrate with a first surface configured to face towards the body fluid. The sensor has a working electrode and an interferent electrode. The interferent electrode and the working electrode are electrically separated layers located adjacently on the first surface. The sensor has a further electrode, the further electrode being a counter electrode, a reference electrode or a counter/reference electrode. The working electrode and the interferent electrode each have a layer of a conductive material. The working electrode has an enzyme whereas the interferent electrode is devoid of enzyme. A method for producing the fully or partially implantable analyte sensor for continuously monitoring analyte concentration in a body fluid is also disclosed.

A biosensor detector device is disclosed suitable for use in measuring membrane fluidity or membrane permeability. The biosensor detector device is formed of a solid substrate having a lipid bilayer compatible surface, a multi-lamellar lipid membrane structure derived from a biological cell and localized on the lipid bilayer compatible surface, an aqueous layer interposed between each lipid bilayer of the multi-lamellar lipid membrane structure. The biological membrane is derived from human red blood cells and localized on the lipid bilayer compatible surface. An electrode forming all or part of the lipid bilayer compatible surface may be used to detect disruptions in the multi-lamellar lipid membrane structure and hemolytic activity in a test sample.

The subject invention provides materials and methods for single-step fluorescence and electrochemical detection of small molecules, e.g., fentanyl and its analogs, in a sample. The subjection invention provides nucleic acids materials, e.g., aptamers (nucleic acid oligonucleotides) that can bind to fentanyl and its analogs with nanomolar affinity and high specificity against illicit drugs, adulterants, and cutting agents commonly existing in seized samples. The method for detecting fentanyl and/or its analogs in a sample comprises contacting the sample with an aptamer-based sensor selective for fentanyl and its analogs, and sensitively, specifically, and rapidly detecting fentanyl and/or its analogs in the sample.

Described herein are nucleic acid-based electrochemical proximity assays (ECPAs) for sample quantification. The invention may also include a biosensor with a sensing mechanism that uses a pair of aptamers or antibodies that bind the target of interest. More specifically, the invention relates to an electrochemical-based read out of a sensing mechanism that uses a nucleic acid-based proximity assay in conjunction with a pair of aptamers or antibodies for sample quantification. The biosensor or a set of biosensors can be used either as a standalone measurement system for a single analyte target or as a component of a multiplexed cartridge for multiple analytes.

The present disclosure provides new approaches in developing templated polymer-based chemical receptors. At least some embodiments of the invention use a stimuli-responsive polymer [e.g., poly-Nisopropylacrylamide (pNIPAM)] as a polymer backbone with the incorporation of functional monomers (for analyte recognition). In at least some embodiments of the invention, vinylferrocene may be used as a redox-active label for electrochemical transduction.

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.

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 of using a graphite electrode to measure a concentration of glucose or methionine from a biological sample is described. A mechanical pencil lead may be used as the graphite electrode, and the biological sample may come from a patient's serum. The glucose or methionine may produce a peak current response within a range of 0.4-0.8 V when the sample is subjected to linear scan voltammetry.

Methods, apparatus, systems, and methods are described that relate to microneedle-assisted aptamer-based electrochemical sensing for label-free, continuous real-time monitoring of biomarkers in a biofluid. One example device for electrochemical monitoring of one or more analytes in a biofluid includes a substrate and at least two microneedles coupled to the substrate. Each microneedle in the at least two microneedles includes a protruded needle structure and an electrode probe structure. The electrode probe structure of a first microneedle in the at least two microneedles includes an aptamer sequence which is specific for a first analyte and the electrode probe structure of the first microneedle is operable as a working electrode for detection of the first analyte using a first electrochemical detection technique.