<p>Chemosensors are powerful and indispensable tools that enable the detection and quantification of chemical substances in diverse gas environments. This Reprint focuses on the advanced materials and techniques that have been developed recently in this field. Those sensors employing inorganic organic hybrid or composite gas-sensitive materials can provide highly sensitive and selective responses to diverse gaseous chemicals via optical electrical and electrochemical signals among others. They can be used to ensure environmental monitoring industrial analysis secure response healthcare and medical diagnosis etc.</p>