The properties and applications of amperometric gas sensors

Abstract

The properties and applications of aniperometric gas sensors are reviewecl. An introductory discussion of the general mechanism o f electrochemical gas reactions atid an outline of the construction of amperometric gas sensors is presented The performance of sensors and the relationship of the sensor's performance to the materials of construction and sensor components are described. The analytical charactcristics of a sensor such as sensitiviv, selectivity, response time and noise are intimately related to the materials chosen for membranes, conductive electrolytes, and active electrocatalysts, as well as the choice o f effective operating conditions. The applications of amperometric gas sensors to specific anaI>rtical problems are discussed in the context of required performance. Finally, this article points out technical gaps and the future direction of amperometric gas sensor research including some potential applications. Keferences that are relevant to the field of amperometric gas sensors are summarized in a table which contains the author's name. the electrochemical reaction, and an exemplary application.

Currently Commercially Available Chemical Sensors Employed for Detection of Volatile Organic Compounds in Outdoor and Indoor Air

“…A result of the redox reaction is generation of electric current being a sensor signal. This signal is proportional to concentration of the analyte present in direct vicinity of the sensor (gas environment) [27,28]. Figure 2 schematically illustrates design of the electrochemical sensor in a three-electrode version with the working (measurement) electrode, counter electrode and reference electrode of constant potential with respect to the working electrode.…”

Gas Diffusion Electrodes for Use in an Amperometric Enzyme Biosensor

“…Reviews on the subject are given by Knake et al [2], Chang et al [3], or Cao et al [4]. Sensors can be classified according to the electrolytes used: aqueous electrolytes, nonaqueous, solids and polymers, or others [4]. Amperometric gas sensors incorporating a liquid electrolyte can be further divided into sensors with an electrode covered by a membrane and a thin electrolyte layer in between (Clarktype), a metallized solid polymer electrolyte (e.g., based on Nafion) in contact with an internal electrolyte solution (here, the metal side faces the gas phase), or as sensors with a metallized membrane electrode, where the metal side of the membrane faces the internal electrolyte [2].…”

“…Their applications as chemical sensors cover, e.g., industrial safety and hygiene, environmental monitoring, automotive, military, or indoor air quality control [1]. Reviews on the subject are given by Knake et al [2], Chang et al [3], or Cao et al [4]. Sensors can be classified according to the electrolytes used: aqueous electrolytes, nonaqueous, solids and polymers, or others [4].…”

Calibration and assessment of electrochemical air quality sensors by co-location with regulatory-grade instruments

“…One of the most commonly used technologies for low-cost AQ sensing is the electrochemical sensor, in which a pollu-tant of interest reacts electrochemically within a cell, drawing a current that is proportional to the analyte concentration (Cao et al, 1992). Modern electrochemical sensors have sensitivities in the parts per billion by volume (ppb) range (Hodgson et al, 1999), enabling sensitive, real-time pollutant measurements.…”