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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.

Bipolar resistive switching using organic molecule is very promising for memory applications owing to their advantages, such as simple device structure, low manufacturing cost, stability, and flexibility. Herein we report Langmuir–Blodgett (LB) and spin-coated-film-based bipolar resistive switching devices using organic material 1,4-bis(di(1H-indol-3-yl)methyl)benzene (Indole1). The pressure–area per molecule isotherm (π–A), Brewster angle microscopy (BAM), atomic force microscopy (AFM), and scanning electron microscopy (SEM) were used to formulate an idea about the organization and morphology of the organic material onto thin films. On the basis of the device structure and measurement protocol, it is observed that the device made up of Indole1 shows nonvolatile resistive random access memory (RRAM) behavior with a very high memory window (∼106), data sustainability (5400 s), device yield (86.7%), and repeatability. The oxidation–reduction process and electric-field-driven conduction are the keys behind such switching behavior. Because of very good data retention, repeatability, stability, and a high device yield, the switching device designed using compound Indole1 may be a potential candidate for memory applications.