This invention provides methods and apparatuses for the rapid assessment of cell permeability by a drug. More particularly, described herein a method of determining membrane permeability (influx and/or efflux) of a cell to a drug, the method including: (a) obtaining a biological sample; (b) dispersing at least one cell from the biological sample to a discrete location; (c) exposing the at least one cell to one member of a drug panel in a drug solution, wherein the drug panel is composed of drugs of a given concentration; (d) incubating the at least one cell from the biological sample in the drug for a given time; (e) obtaining at least one electro-analytical measurement of the discrete location adjacent the at least one cell.

This invention provides methods and apparatuses for the rapid assessment of cell permeability by a drug. More particularly, described herein a method of determining membrane permeability (influx and/or efflux) of a cell to a drug, the method including: (a) obtaining a biological sample; (b) dispersing at least one cell from the biological sample to a discrete location; (c) exposing the at least one cell to one member of a drug panel in a drug solution, wherein the drug panel is composed of drugs of a given concentration; (d) incubating the at least one cell from the biological sample in the drug for a given time; (e) obtaining at least one electro-analytical measurement of the discrete location adjacent the at least one cell.

A surface modified electrode and a method of preparing the surface modified electrode are provided. The surface modified electrode includes a glassy carbon electrode and a coating of a compound of formula I disposed on the glassy carbon electrode. The present disclosure also relates to a method of preparing the surface modified electrode. The method includes depositing a slurry of the compound of Formula I on the glassy carbon electrode to form a film and coating a polymer matrix on the film to obtain the surface modified electrode. The present disclosure also relates to a method of preparing the compound of Formula I. The method includes condensing 4-bromobenzaldehyde (4-BBD) and 4-methyl-benzenesulphonylhydrazine (4-MBSH), to obtain a first mixture and precipitating the first mixture to obtain the compound of Formula I. The surface modified electrode is used in an electrochemical sensor for the detection of metal ions. ##STR00001##

Disclosed is an assay for determining resistance in a target cell or tissue to a therapy associated with cellular stress using chemical microscopy and high-throughput single cell analysis to determine functional metabolic alteration, including determining metabolic reprogramming in a target cell or tissue to a therapy associated with cellular stress, and methods of using the assays.

Disclosed is an assay for determining resistance in a target cell or tissue to a therapy associated with cellular stress using chemical microscopy and high-throughput single cell analysis to determine functional metabolic alteration, including determining metabolic reprogramming in a target cell or tissue to a therapy associated with cellular stress, and methods of using the assays.

A method is provided for subtractively processing a layer of etchable material formed over an electrically conductive surface region of a workpiece. The workpiece is immersed in a liquid solution, generally but not exclusively a conductive solution, that comprises an etchant for the etchable material, so that etching of the etchable material is initiated. An electric circuit is connected to include a control electrode, a reference electrode, and the electrically conductive surface region of the workpiece. The electric circuit is used to monitor the development process dynamically at each of a plurality of intervals during the etching. The etching is terminated when the electrochemical signal satisfies a criterion indicating that the etching is complete.

Electrochemical sensors useful for detection of heavy metals are described. The electrochemical sensors can be made by forming a layer of graphene oxide on a working electrode, forming a layer of carbon nanotubes (CNTs) on the layer of graphene oxide, and forming a layer of gold nanostars on the layer of CNTs.

Closed-loop systems and methods for controlling pH. The system includes a working electrode, a counter electrode, a reference electrode, a first ion-sensitive field-effect transistor (ISFET), a second ISFET, and an electronic controller. The working electrode, the counter electrode, the reference electrode, and a first sensing terminal of the first ISFET are immersible in an active solution. A second sensing terminal of the second ISFET is immersible in a reference solution. The electronic controller is configured to apply a first amount of current or voltage to the working electrode and determine a differential voltage between the first ISFET and the second ISFET. The electronic controller is also configured to set a second amount of current or voltage to reduce a difference between the differential voltage and a target voltage. The electronic controller is further configured to apply the second amount of current or voltage to the working electrode.

Nanostructured microelectrodes and biosensing devices incorporating the same are disclosed herein.

Nanostructured microelectrodes and biosensing devices incorporating the same are disclosed herein.