Various embodiments disclose an electronic circuit for an electrochemical gas sensor. The electronic circuit comprises a first switching element electrically coupled to a reference terminal of the electrochemical gas sensor and a ground voltage terminal. Further, the electronic circuit comprises a second switching element electrically coupled to a sensing terminal of the electrochemical gas sensor and the ground voltage terminal. In an instance in which the electrochemical gas sensor is powered OFF, the first switching element and the second switching element are configured to electrically couple the reference terminal and the sensing terminal to the ground voltage terminal such that current generated when the sensing electrode and the target gas react while the electrochemical gas sensor is powered OFF flows to the ground voltage terminal and the potential of the reference terminal and the sensing terminal remain the equal.

A sensor apparatus for detecting a heavy metal in a sample.

In a general aspect, an apparatus can include a first carbon nanotube array that is patterned to define a first electrode having a first plurality of electrode segments. The apparatus can also include a second carbon nanotube array that is patterned to define a second electrode having a second plurality of electrode segments. The second plurality of electrode segments can be interdigitated with the first plurality of electrode segments. The apparatus can further include a biorecognition agent disposed on a surface of the first electrode and disposed on a surface of the second electrode. The first plurality of electrode segments can each have a height-to-width aspect ratio of at least 1 to 1.

A sensor device is provided to sample data from a fluid in a sealed environment. The sensor comprises a housing and a diamond within the housing. The housing is formed such that the device is reversibly insertable into the sealed environment so that the diamond directly interfaces with the sealed environment.

An electrode composed of a substrate including a graphene layer coated on a first metal; and a complex including a second metal deposited on the substrate and a hydroxide of the first metal, where the complex is in the form of core-shell in which the second metal is a core and the hydroxide of the first metal is a shell, and the second metal has a higher standard reduction potential than the first metal. The graphene-coated metal foam of the present invention is the first case that proves not only theoretically but also by experiment that the remarkable catalytic ability reducing other metals (Au, Pt, Ag, and Cu, etc.) with a higher reduction potential than the metal by graphene coated on the metal surface it electroless deposition without additional reductant or electrical reduction conditions is due to the electrical double layer or interfacial dipole induced between the graphene and the metal.

A Prussian blue/zinc oxide-carbon nanotube composite is provided, the nanotube composite being selective and sensitive for detection of hydrogen peroxide, which is important for screening for early cancer detection, monitoring cardiovascular disease, detecting onset of food spoilage, and enzymatic reactions that produce hydrogen peroxide as a byproduct. Also provided are methods using said zinc oxide-carbon nanotube composite in which standard addition is used in combination with chronoamperometry detection to quantify the level of hydrogen peroxide in a biological sample.

Methods, electrodes, and sensors for chlorine species sensing using pseudo-graphite are disclosed. In one illustrative embodiment, a method may include coating a pseudo-graphite material onto a surface of an electrode substrate to produce a pseudo-graphite surface. The method may also include exposing the pseudo-graphite surface to a sample to detect chlorine species in the sample.

Provided are devices and methods for a rapid, non-perturbative and energy-efficient technique for pH sensing based on a flexible graphene electrode. This technique does not require the application of gate voltage or source-drain bias, and demonstrates fast pH-characterization with precision. The disclosed technology is suitable for in vivo monitoring of tumor-induced pH variation in tissues and detection of pH changes as required in a DNA sequencing system.

Embodiments of the present disclosure pertain to ion-selective electrodes that include a metal-organic framework and an electrode surface. The metal-organic framework is associated with the electrode surface in a manner that forms an interface between the metal-organic framework and the electrode surface. Additional embodiments pertain to methods of detecting an ion in a sample by associating the sample with the ion-selective electrodes of the present disclosure. The metal-organic frameworks of the ion-selective electrodes mediate ion-to-electron transduction through the interface between the metal-organic and the electrode surface. Thereafter, the presence or absence of the ion in the sample is detected by detecting a change in potential of the ion-selective electrode and correlating the change in the potential to the presence or absence of the ion. The metal organic frameworks may simultaneously mediate ion sensing and ion-to-electron transduction through the interface between the metal-organic frameworks and the electrode surface.

The present disclosure relates to an electrode for measuring an analyte. The electrode includes a first base layer, a first electrode layer upon the first base layer, and a second base layer. The first electrode layer is arranged between the first base layer and the second base layer. The first base layer includes a conductive metal, a conductive metal alloy, or carbon. The first electrode layer includes ruthenium metal, a ruthenium based metal alloy, nickel metal, or a nickel based metal alloy. The first base layer is made of different elements than the first electrode layer. The first base layer is more conductive than the first electrode layer.