Disclosed are methods and devices for biomolecular detection, comprising a nanopipette, exemplified as a hollow inert, non-biological structure with a conical tip opening of nanoscale dimensions, suitable for holding an electrolyte solution which may contain an analyte such as a protein biomolecule to be detected as it is passed through the tip opening. Biomolecules are detected by specific reaction with peptide ligands chemically immobilized in the vicinity of the tip. Analytes which bind to the ligands cause a detectible change in ionic current. A sensitive detection circuit, using a feedback amplifier circuit, and alternating voltages is further disclosed. Detection of IL-10 at a concentration of 4 ng/ml is also disclosed, as is detection of VEGF.

A method for measuring a concentration of an analyte in a bio-sample using an electrochemical bio-sensor according to an exemplary embodiment of the present invention is characterized by a step of obtaining predetermined features from induced currents obtained by applying a DC voltage according to chronoamperometry in which, after a whole blood sample is injected to the electrochemical bio-sensor, a concentration of an analyte is obtained from an induced current obtained by applying a DC voltage for a certain time and from all induced currents obtained by further applying several step-ladder perturbation potentials for a short time subsequent to the DC voltage for the certain time, and is also characterized by minimization of a measurement error caused by a hindering material by forming a calibration equation by combining the at least one feature in a function and optimizing various conditions of the bio-sample through DeletedTextsmultivariable analysis. With this configuration, a perturbation potential application method added to a conventional measurement method can maintain a bio-sensor and a measuring apparatus already used, a line used in the measuring apparatus, and calibration of amperometry as they are, improve accuracy in measurement by effectively minimizing a matrix interference effect of a background material in a bio-sample, particularly an inaccuracy caused by a change in hematocrit, and also remarkably improve accuracy in measurement by simply upgrading a measurement program of a conventional measuring apparatus.

A chemical sensor for heavy metal detection is provided. The chemical sensor includes an inlet, a chamber in fluid communication with the inlet, and an outlet in fluid communication with the chamber. A working electrode is provided in the chamber. The working electrode includes a plurality of protrusions extending into a fluid flow path in the chamber beyond a boundary layer of the fluid flow path. The chemical sensor also includes a reference electrode, a counter electrode, and a plurality of contact pads electrically connected to respective ones of the working electrode, the reference electrode and the counter electrode.

A chemical sensor for heavy metal detection is provided. The chemical sensor includes an inlet, a chamber in fluid communication with the inlet, and an outlet in fluid communication with the chamber. A working electrode is provided in the chamber. The working electrode includes a plurality of protrusions extending into a fluid flow path in the chamber beyond a boundary layer of the fluid flow path. The chemical sensor also includes a reference electrode, a counter electrode, and a plurality of contact pads electrically connected to respective ones of the working electrode, the reference electrode and the counter electrode.

A device for measuring pH levels and contaminant concentration includes an electrode assembly that is electrically coupled to a control unit. The electrode assembly includes a first contact electrically coupled to a reference electrode, a second contact electrically coupled to a working electrode, and a third contact electrically coupled to a counter electrode. The working electrode may be modified to include a cysteine functionalized graphene oxide with polypyrrole nanocomposite. In operation, the control unit may apply a complex signal to the working electrode via the second contact in order to adhere and subsequently strip contaminant ions from the fluid sample to the working electrode. During this process, a current may be measured across the working electrode and the counter electrode to measure contaminant ion concentration. The pH of the fluid sample may also be determined by a current measured across the reference electrode and the counter electrode. In some examples, the pH may be used to calibrate the measured levels of the contaminant ions.

A device for measuring pH levels and contaminant concentration includes an electrode assembly that is electrically coupled to a control unit. The electrode assembly includes a first contact electrically coupled to a reference electrode, a second contact electrically coupled to a working electrode, and a third contact electrically coupled to a counter electrode. The working electrode may be modified to include a cysteine functionalized graphene oxide with polypyrrole nanocomposite. In operation, the control unit may apply a complex signal to the working electrode via the second contact in order to adhere and subsequently strip contaminant ions from the fluid sample to the working electrode. During this process, a current may be measured across the working electrode and the counter electrode to measure contaminant ion concentration. The pH of the fluid sample may also be determined by a current measured across the reference electrode and the counter electrode. In some examples, the pH may be used to calibrate the measured levels of the contaminant ions.

Disclosed are methods and devices for biomolecular detection, comprising a nanopipette, exemplified as a hollow inert, non-biological structure with a conical tip opening of nanoscale dimensions, suitable for holding an electrolyte solution which may contain an analyte such as a protein biomolecule to be detected as it is passed through the tip opening. Biomolecules are detected by specific reaction with peptide ligands chemically immobilized in the vicinity of the tip. Analytes which bind to the ligands cause a detectible change in ionic current. A sensitive detection circuit, using a feedback amplifier circuit, and alternating voltages is further disclosed. Detection of IL-10 at a concentration of 4 ng/ml is also disclosed, as is detection of VEGF.

Disclosed are methods and devices for biomolecular detection, comprising a nanopipette, exemplified as a hollow inert, non-biological structure with a conical tip opening of nanoscale dimensions, suitable for holding an electrolyte solution which may contain an analyte such as a protein biomolecule to be detected as it is passed through the tip opening. Biomolecules are detected by specific reaction with peptide ligands chemically immobilized in the vicinity of the tip. Analytes which bind to the ligands cause a detectible change in ionic current. A sensitive detection circuit, using a feedback amplifier circuit, and alternating voltages is further disclosed. Detection of IL-10 at a concentration of 4 ng/ml is also disclosed, as is detection of VEGF.

A sensor for the detection of lead includes a substrate, a working electrode formed on a surface of the substrate, a counter electrode formed on the surface of the substrate, a dielectric layer covering a portion of the working electrode and counter electrode and defining an aperture exposing other portions of the working electrode and counter electrode. The working electrode includes a metalized film with working surface and a monolayer (or bilayer) of bismuth deposited on the working surface by underpotential deposition.

A sensor for the detection of lead includes a substrate, a working electrode formed on a surface of the substrate, a counter electrode formed on the surface of the substrate, a dielectric layer covering a portion of the working electrode and counter electrode and defining an aperture exposing other portions of the working electrode and counter electrode. The working electrode includes a metalized film with working surface and a monolayer (or bilayer) of bismuth deposited on the working surface by underpotential deposition.