Imidazole and triazole head group-containing polydiacetylenes for colorimetric monitoring of pH and detecting HCl gas

The family of conjugated polymers known as polydiacetylenes (PDAs) has been extensively utilized in designing stimuli-responsive colorimetric and fluorometric sensors. In the current study, we have developed highly sensitive and rapidly responsive colorimetric chemosensors composed of PDAs bearing imidazole (PDA-Im) and triazole (PDA-Ta) head groups for the determination of pH and the detection of HCl gas. In solution, PDA-Im and PDA-Ta display distinct colorimetric changes from blue to red accordingly in response to pH changes. Also, a PDA-Im film was fabricated to detect HCl by a visibly observed blue-to-red color change.