Provided herein is technology relating to electrochemical detection of analytes and particularly, but not exclusively, to a double junction reference electrode, methods of using a double junction reference electrode, handheld or robotically manipulable apparatuses comprising a double junction reference electrode, and systems comprising a double junction reference electrode.

Disclosed herein are embodiments of a gas sensor system and methods of analyzing data therefrom. In embodiments, a gas sensor system includes one or more gas preconcentrator modules and one or more gas sensor modules. Each gas preconcentrator module includes a substrate that has a top surface having a gas adsorbent material attached to the top surface and has an electrical heater element for heating each preconcentrator module to release adsorb gases to the sensor. The gas sensor modules and the gas preconcentrator modules are in fluid communication with each other. The gas sensor modules responses are readout in parallel multiple times as the preconcentrators are heated yielding a 2-dimensional gas spectrum. The gas sensor output data is analyzed and compared to a library of known data to analyze the gas composition.

Disclosed herein are embodiments of a gas sensor system and methods of analyzing data therefrom. In embodiments, a gas sensor system includes one or more gas preconcentrator modules and one or more gas sensor modules. Each gas preconcentrator module includes a substrate that has a top surface having a gas adsorbent material attached to the top surface and has an electrical heater element for heating each preconcentrator module to release adsorb gases to the sensor. The gas sensor modules and the gas preconcentrator modules are in fluid communication with each other. The gas sensor modules responses are readout in parallel multiple times as the preconcentrators are heated yielding a 2-dimensional gas spectrum. The gas sensor output data is analyzed and compared to a library of known data to analyze the gas composition.

A gas permeable, liquid impermeable membrane for use with gas sensors consists of a film forming polymer which incorporates nanoparticles selected to improve one or more of the following: permeability to gases, to selectively regulate permeability of selected gases through the membrane, to inhibit microbial growth on the membrane. A capsule shaped container consists of wall material biocompatible with a mammal GI tract and adapted to protect the electronic and sensor devices in the capsule, which contains gas composition sensors, pressure and temperature sensors, a microcontroller, a power source and a wireless transmission device. The microprocessor receives data signals from the sensors and converts the signals into gas composition and concentration data and temperature and pressure data for transmission to an external computing device. The capsule wall incorporates gas permeable nano-composite membranes with embedded catalytic and nano void producing nanoparticles, enhancing the operation, selectivity and sensitivity of the gas sensors.

The invention relates to an electrochemical gas sensing apparatus for sensing one or more analytes, such as NO.sub.2 and/or O.sub.3, in a sample gas and a method of using same. The apparatus uses Mn.sub.2O.sub.3 as a filter for ozone. The Mn.sub.2O.sub.3 may take the form of a powder which may be unmixed, mixed with various PTFE particles sizes, formed into a solid layer deposited onto a membrane and/or pretreated with NO.sub.2.

The invention relates to an electrochemical gas sensing apparatus for sensing one or more analytes, such as NO.sub.2 and/or O.sub.3, in a sample gas and a method of using same. The apparatus uses Mn.sub.2O.sub.3 as a filter for ozone. The Mn.sub.2O.sub.3 may take the form of a powder which may be unmixed, mixed with various PTFE particles sizes, formed into a solid layer deposited onto a membrane and/or pretreated with NO.sub.2.

Systems and methods for concentrating an analyte preparatory to analysis thereof include processing the effluent of an analyte concentrator to produce an eluent for eluting an analyte retained in the same or separate concentrator, and systems implementing the same. The analyte concentrator system connects the effluent outlet of an analyte concentrator column to an eluent generation module such that the substantially analyte-free effluent discharged from the analyte concentrator column passes fluidly into the eluent generation module. Eluent generated from the substantially analyte-free effluent in the eluent generation module is likewise substantially free of the analyte. The systems and methods can minimize and/or (substantially) eliminate background signal during analysis of the concentrated analyte.

A hydrogen detector for gas and fluid media is disclosed. The detector includes a selective membrane and a housing. Within the housing is a potential measuring unit and a ceramic sensing element made of a solid electrolyte. A standard electrode is located within a cavity of the ceramic sensing element and a porous platinum electrode is applied to an external layer of the ceramic sensing element. A potential measuring unit passes through a sealed lead-in at the upper end of the housing and is brought out to the standard electrode. The selective membrane, which is attached to a hole in the end of the lower bushing, is closed with a plug. The cavity limited by the inner surface of the lower bushing, the external part of the bottom of the ceramic sensing element and the inner surfaces of the selective membrane and the plug is leak-tight.

A hydrogen detector for gas and fluid media is disclosed. The detector includes a selective membrane and a housing. Within the housing is a potential measuring unit and a ceramic sensing element made of a solid electrolyte. A standard electrode is located within a cavity of the ceramic sensing element and a porous platinum electrode is applied to an external layer of the ceramic sensing element. A potential measuring unit passes through a sealed lead-in at the upper end of the housing and is brought out to the standard electrode. The selective membrane, which is attached to a hole in the end of the lower bushing, is closed with a plug. The cavity limited by the inner surface of the lower bushing, the external part of the bottom of the ceramic sensing element and the inner surfaces of the selective membrane and the plug is leak-tight.

Fuel cell gas sensors using an aperture in a fuel cell gas sensor that allows for determination of a gas proportion in a sample that includes more gas than could otherwise be safely sampled. The aperture is adjustable between an open and a closed state. The amount of the gas of interest exposed to the fuel cell may be adjusted by adjusting the amount of time that the aperture is in the open state. Alternatively, the amount of the gas of interest exposed to the fuel cell may be adjusted by adjusting the size of the aperture.