Recent advances in optochemical sensors for the detection of H2, O2, O3, CO, CO2 and H2O in air

Room temperature ozone sensing properties of p-type transparent oxide CuCrO2

“…However, these standard methods often require sophisticated air sampling and expensive analytical equipment. Semiconductor sensors, such as the sensors based on WO 3 and In 2 O 3 , are the most economical sensors, but they have a general drawback that they require operation at high temperatures of more than 150 • C [1,2]. Furthermore, the response reversibility of the sensor at high ozone concentration is often poor because of the strong oxidizing property of ozone [3].…”

“…Semiconductor sensors, such as the sensors based on WO 3 and In 2 O 3 , are the most economical sensors, but they have a general drawback that they require operation at high temperatures of more than 150 • C [1,2]. Furthermore, the response reversibility of the sensor at high ozone concentration is often poor because of the strong oxidizing property of ozone [3]. Though room temperature sensing of ozone has been achieved in In 2 O 3 and ZnO by the activation of the UV light, the usage of UV light limits its application in simple, low-cost and compact sensors [4,5].…”

Classification and Applications of Humidity Sensors: A Review

“…In recent years, optochemical sensors [63][64] have attracted attention because of their remote analysis capability, high sensitivity, and compactness. Most of the optochemical sensors are composed of a dye-dispersed polymer in which optical intensity of the absorption, florescence or phosphorescence peak depends upon the chemical species and their concentrations.…”

Stimuli‐Driven Assembly of Chromogenic Dye Molecules: a Versatile Approach for the Design of Responsive Polymers

“…Consequently, a broad range of transduction techniques have been exploited for water sensors. Systems that display reversible color changes include charge-transfer forming dyes [69], solvatochromic dyes [70], chromogenic polymers [71], and inorganic salts [72]. The self-assembly-based moisture sensors described here rely on a different mechanism, which makes their properties fundamentally different from the known systems: they display an irreversible color change upon exposure to moisture, which makes them useful as ''moisture history'' indicators.…”