Improved methods of manufacturing highly sensitive and selective electrochemical biosensors are provided. The method may comprise washing the nanowell array electrodes of the biosensors with ferricyanide, preferably potassium ferricyanide. The method may also comprise washing the electrodes of the biosensors with methylene blue (i.e., methylthioninium chloride), either in addition to the ferricyanide and/or H2SO4 washing steps, or without the ferricyanide and/or H.sub.2SO.sub.4 washing steps.

A device, liquid handling cartridge and related method for detecting the presence or absence of a chemical or biological target within a sample. The method includes the steps of: providing an electrochemical cell with a first electrode module and a second electrode; providing an electronic component between the first electrode module and the second electrode; introducing the sample into the electrochemical cell; measuring the potential difference between the first electrode module and second electrode; and confirming the presence of the chemical or biological target if the measured potential difference exceeds a predetermined threshold value.

A method for detecting at least one analyte by electrochemical detection, a working electrode of an analyte sensor and an analyte sensor for detecting at least one analyte in a sample by electrochemical detection. The method comprises contacting a fluid sample suspected to comprise the at least one analyte with the surface of an electrode comprising a binding agent capable of binding to the analyte; contacting the fluid sample with a detection agent comprising a further binding agent capable of binding to the analyte and a label, the label comprising a metal nanoparticle with a standard redox potential E° between 0 V and 1.2 V forming a detection complex on the surface of the electrode comprising the binding agent, the detection agent and the analyte precipitating at least a part of the label onto the electrode surface; and detecting the analyte by electrochemical detection.

Disclosed herein are an apparatus for electrically assessing and/or manipulating cells. One aspect is directed to electrically mapping cells on the surface of the semiconductor substrate via cross-electrode impedance measurements. Further according to some aspects, the electrode array allows for spatially addressable electrical stimulation and/or recording of electrical signals in real-time using the CMOS circuitry. Some of these aspects are directed to using an electrode array to perform cell patterning through electrochemical gas generation, and extracellular electrochemical mapping.

The subject invention provides methods for fabricating electrochemical aptamer-based (E-AB) sensors with enhanced sensitivity, signal-to-noise ratios, LOD, and improved stability and reproducibility. The subject invention also provides methods for aptamer immobilization on the surface of the electrode, which favors sufficient spacing between aptamers at the microscale to achieve optimal target recognition, folding, and signal transduction. The E-AB sensors of the subject invention provide superior sensing regardless of the sequence or structure of the bound aptamers or the physiochemical properties of the target.

A labeled nucleotide includes a nucleotide, a linking molecule attached to a phosphate group of the nucleotide, and a redox-active charge tag attached to the linking molecule. The redox-active charge tag is to be oxidized or reduced by an electrically conductive channel when maintained in proximity of a sensing zone of the electrically conductive channel.

Example implementations include a method of applying a voltage pulse having a magnitude within a biochemical voltage window associated a biochemical, obtaining a response current from a biochemical sensor electrode, generating a biochemical response voltammogram based on the response current, extracting a current peak from the biochemical response voltammogram, and generating a biochemical concentration based on the current peak. Example implementations further include a method of applying a differential pulse sequence including the voltage pulse to the reference electrode. Example implementations further include a method of applying the differential pulse sequence further comprises applying the differential pulse sequence to the reference electrode at an increasing voltage step.

Provided is a preparation method for an immunoelectrode. The immunoelectrode comprises a substrate, a gold layer, a conductive polymer layer and an antibody layer. The substrate, the gold layer, the conductive polymer layer and the antibody layer are sequentially attached from bottom to top. The preparation method for the immunoelectrode specifically comprises the following steps: (1) preparing the conductive polymer layer: preparing a polypyrrole layer on a gold-plated substrate to obtain a polypyrrole/gold-plated substrate; (2) preparing the immunoelectrode: preparing the antibody layer on the polypyrrole layer to obtain an antibody/polypyrrole/gold-plated substrate; and (3) forming an immunoelectrode system: fixing a bare gold-plated substrate to the outer side of the antibody/polypyrrole/gold-plated substrate to obtain the immunoelectrode system. A polypyrrole material is used for fixing an antibody of a biological recognition element and immobilizing the antibody on the immunoelectrode.

Analyte sensors and methods for fabricating analyte sensors are provided. In an exemplary embodiment, a method for fabricating a planar flexible analyte sensor includes sputtering platinum onto a polyester base layer to form a layer of platinum. The method includes patterning the layer of platinum to form working electrodes and additional electrodes. Further, the method includes forming an insulating dielectric layer over the base layer, wherein the insulating dielectric layer is formed with openings exposing portions of the working electrodes and portions of the additional electrodes. Also, the method includes partially singulating individual sensors from the base layer, wherein each individual sensor is connected to the base layer by a tab. The method further includes depositing an enzyme layer over the exposed portions of the working electrodes and coating the working electrodes with a glucose limiting membrane.

Fluorophores are used during the synthesis of oligonucleotides to achieve real-time quality control of the synthesis process. Fluorescence may indicate successful addition of individual nucleotides to a growing oligonucleotide strand or removal of a blocking group. The oligonucleotides may be created by enzymatic synthesis using terminal deoxynucleotidyl transferase (TdT). The synthesis is performed on an addressable array so that oligonucleotides with different sequences are created in parallel on different regions of the array. The oligonucleotide sequences are predetermined and the locations of synthesis on the array are controlled. Observed fluorescence is compared to expected locations of fluorescence as determined by the oligonucleotide sequences and the arrangement on the array. Thus, the fidelity of oligonucleotide synthesis is checked as synthesis proceeds. If a variation is found, a mitigating action is taken such as repeating addition of a species of nucleotide or repeating a deblocking step.