Polydiacetylene-N-1-Hexadecyl Imidazole Mixed Film and Its Application toward the Sensing of Volatile Organic Compounds, Gasoline, and Pollution Level in Car Exhaust

Polydiacetylenes have gained increasing attention as promising smart materials owing to their brilliant blue-to-red color transition in response to various microenvironmental perturbations. In this communication, we report a paper-based naked-eye colorimetric sensor array comprising 10, 12-tricosadiynoic acid (TCDA) and N-1-hexadecyl imidazole derivatives. Sensor arrays were prepared onto a filter paper using the suction technique, followed by UV irradiation. In this sensor system, the clay material hectorite was used as the host/support to enhance the mechanical stability of the paper-based sensor. Both the TCDA-clay and TCDA-clay-N-1-hexadecyl imidazole sensors were studied to sense 12 different volatile organic compounds (VOCs). Interestingly, the TCDA-clay sensor responded to 7 VOCs, whereas the TCDA-clay-N-1-hexadecyl imidazole sensor responded to all 12 VOCs. The presence of N-1-hexadecyl imidazole was advantageous with respect to response time, concentration, and the number of VOCs. Interestingly, the designed sensors also showed distinct response toward gasoline and the presence of kerosene in gasoline. Applications of the designed sensors toward the pollution level of car exhaust have also been demonstrated successfully.