Direct detection of ultralow trace amounts of isocyanates in air using a fluorescent conjugated polymer

A fluorescence sensory polymer containing the pentiptycene and tetraphenylethylene units linked by acetylene was synthesized for direct detection of isocyanates in air. Eight industrially available aliphatic and aromatic isocyanates were tested. The polymer film shows a rapid fluorescence quenching response to any type of isocyanates with a ppt level of detection limit, which is much lower than the permissible exposure limit of 5 ppb.