Calixarenes based materials for gas sensing applications: a review

Abstract

The development of sensing materials based on calixarenes to enable the detection, monitoring, and quantification of hazardous gases or pollutants present in our environment is discussed in the present review due to the enormous importance of this area. Calix[n]arenes are being used as molecular receptors to trap gaseous vapors at very low concentration owing to variable cavity dimensions and the presence of two distinct (hydrophobic and hydrophilic) regions. Calixarenes are sensitive and specific for detection due to their porous structure, which allows diffusion inside the film. A number of surface characterization techniques including mass sensitive quartz micro balance/quartz crystal microbalance, the Langmuir–Blodget films, and surface acoustic wave oscillator are being employed along with different calixarenes to measure the interaction or association between host (calixarenes) and the guest (gas molecules). Combining different scaffolds offer an additional advantage in the search for successful new sensing devices. The review highlights the new development in the area of monitoring and detection of hazardous gases through less time consuming, sensitive, reproducible and reliable monitoring techniques involving the use of appropriate calix[n]arene as sensing materials.