Biphenyl-rGO composite room temperature gas sensor for enhanced amine sensing.

Amines, which are classified as volatile organic compounds (VOCs), serve a variety of purposes in the fields of environmental monitoring, food safety, and healthcare diagnosis. The present technique for detecting amine levels involves sophisticated setups and bulky equipment. Here. In this study, a chemoresistive gas sensor is developed that is cost-effective and easy to operate at room temperature (RT). The sensor is designed specifically for the detection of Ammonia, dimethylamine (DMA), trimethylamine (TMA), and total volatile basic nitrogen (TVB-N). Using biphenyl-reduced graphene oxide (B-rGO) composite gas sensors effectively addresses the issues of low sensitivity-selectivity and long-term instability commonly observed in conventional amine sensors. B-rGO sensor produced sensitivity of ∼3500 and selectivity above 30 for TVB-N sensing. The sensor is stable for temperature fluctuations below 50 °C and shows stable sensing response for period of over 3 months. A Chemoresistive B-rGO sensor was developed using an ultrasonic spray deposition system with optimized flow rate of 50 mL/h. Rapid evaporation of solvent using hot plate has resulted in unique morphology for B-rGO film sensors. The highest sensitivity, ∼836, is obtained for 100 ppm of ammonia with ammonia > DMA > TMA as a sensitivity order. B-rGO showed almost seven times higher amine sensitivity than rGO which highlights the importance of biphenyl in the B-rGO composite. Sensor calibration curve has been presented in the study to understand change in the sensitivity of sensor with increasing analyte gas concentration. The calibration curve has an average R-squared value of 0.98.

Boron difluoride formazanates with thiophene and 3,4-ethylenedioxythiophene capping and their electrochemical polymerization.

We report here the first example of BF2 formazanates with thiophene capping and their π-conjugated polymers in the form of electroactive uniform thin films by electrochemical polymerization. These new formazanates and their polymers possess panchromatic absorption with low lying frontier molecular orbitals. With small band gaps (1.5-1.8 eV), they are good candidates for organic electronics and light-harvesting applications. A computational study on the charge transport properties of BF2 formazanates with 3,4-ethylenedioxythiophene (EDOT) indicates an ambipolar semiconductor nature.