A carbon nanotube-based reference electrode and an all-carbon nanotube microelectrode assembly for electrochemical sensing and specialized analytics are disclosed, along with methods of manufacture, and applications including detection of ionic species including heavy metals in municipal and environmental water, monitoring of steel corrosion in steel-reinforced concrete, and analysis of biological fluids.

Embodiments of the disclosed technology include depositing a passivation layer onto a surface of a wafer that may include a graphene layer. The passivation layer may protect and isolate the graphene layer from electrical and chemical conditions that may damage the graphene layer. As such, the passivation layer may further protect the graphene sensor from being damaged and impaired for its intended use. Additionally, the passivation layer may be patterned to expose select areas of the graphene layer below the passivation layer, thus creating graphene wells and exposing the graphene layer to the appropriate chemicals and solutions.

Fire present invention relates to new electrochemical probes for the measure of an analyte selected from the group consisting of: free chlorine, chlorine dioxide, total chlorine and peracetic acid; characterized in that said probe includes at least a printed electrode nano- or micro-structured whit a nano- or micromaterial selected from the group consisting of: nano- or microparticies of carbon black and/or nano- or microparticles of a metal selected from the group consisting of gold, silver, platinum, copper and combinations or alloys thereof.

Techniques and systems are disclosed for implementing textile-based screen-printed amperometric or potentiometric sensors. The chemical sensor can include carbon based electrodes to detect at least one of NADH, hydrogen peroxide, potassium ferrocyanide, TNT or DNT, in liquid or vapor phase. In one application, underwater presence of chemicals such as heavy metals and explosives is detected using the textile-based sensors.

A process for activating the surface of an electrode based on DLC amorphous carbon by an electrochemical treatment including at least the following steps (i) and (ii), carried out in this order: (i) applying, to the electrode, an electrical excitation in the form of an alternation of cathodic and anodic electrical pulses, these being current or voltage pulses, in contact with an aqueous electrolyte including at least one oxidizing species of a redox pair having a standard potential, at ambient temperature and atmospheric pressure, denoted E0, strictly greater than 0, and at least one base salt; and (ii) applying, to the electrode that was previously subjected to step (i), an electrical excitation in the form of an alternation of cathodic and anodic electrical pulses, these being voltage pulses, in contact with an aqueous electrolyte devoid of electroactive species.

Methods, electrodes, and electrochemical devices using surface-modified pseudo-graphite are disclosed. In one illustrative embodiment, a method may include depositing a pseudo-graphite material onto a surface of an electrode substrate to produce a pseudo-graphite material surface. The method may also include modifying the pseudo-graphite material surface to alter electrochemical characteristics of the electrode.

A nonenzymatic biosensor based on a metal-modified porous boron-doped diamond electrode, and a method for preparing the same and use thereof are provided. A working electrode of the nonenzymatic biosensor is a metal-modified porous boron-doped diamond electrode including a silicon wafer substrate and an electrode working layer arranged on a surface thereof, the electrode working layer is a porous boron-doped diamond layer modified with metal nanoparticles, and a pore surface of the porous boron-doped diamond layer contains an sp.sup.2 phase. In the present invention, by combining chemical vapor deposition and magnetron sputtering and by means of a tubular atmosphere annealing furnace and an electrochemical workstation, the preparation of a multi-metal-modified porous boron-doped diamond composite electrode is realized. The electrode has the characteristics of high sensitivity, stability, and resolution, and can be widely used in the fields of the construction of electrochemical biosensors, the detection of heavy metals, etc.

A gas sensor having a housing with first and second chambers featuring a porous separator located there between. The first chamber of the sensor being connected to atmosphere via a gas diffusion aperture. The gas sensor having a sensing electrode disposed within the first chamber and at least a second electrode disposed within the second chamber. The sensor having an ionic liquid electrolyte disposed within the second chamber where the sensing electrode and at least second electrodes comprise platinum.

Embodiments of the invention are directed to a system for detecting neurotransmitters. A non-limiting example of the system includes a porous electrode. A system can also include a pH sensor attached to the porous electrode, wherein the pH sensor includes a sensing electrode and a reference electrode. The system can also include electronic circuitry in communication with the pH sensor.

An online calibration system for an electrochemical sensor. The calibration system comprises a calibration electrode coupled with a redox species, where the redox species is configured to control a pH of a reference solution local to the calibration electrode, such that when a voltammetric signal is applied to the calibration electrode the output generated from the calibration system is determined by the local environment pH. The output signal from the calibration system is used to calibrate a reference potential generated by a reference system of the electrochemical sensor to correct for drift in the reference potential when the electrochemical sensor is being used. The calibration electrode may be disposed in a reference cell of the electrochemical sensor.