One-step fabrication of ammonia sensor by electrospinning PS-b-PMA nanofibers on quartz crystal microbalance

One-step process of poly (styrene-block-maleic acid) (PS-b-PMA) nanofibers/quartz crystal microbalance (QCM) combined system was proposed as a novel ammonia detection in this research. The PS-b-PMA nanofibrous membranes were deposited on the QCM electrode via electrospinning technique directly, which could retain the intrinsic high specific surface area of PS-b-PMA nanofibers, and much simplify ammonia detection process. Experimental results showed that the specific surface area (SSA) of the PS-b-PMA membranes was controllable by adjusting the weight ratios of the mixture solvents of acetone/N,N-dimethylformamide. The PS-b-PMA nanofibers/QCM sensor system exhibited excellent ammonia sensing performances, such as rapid response, excellent reversibility and high sensitivity (low detection limit at 1.5 ppm) at room temperature. The frequency responses showed a linear growth with the injected ammonia concentration ranging from 1.5 ppm to 50 ppm. In addition, a linear relationship between the frequency responses per unit injected gas concentration (Hz/ppm) and different SSAs was found. These sensing results indicated that QCM sensor on the basis of PS-b-PMA nanofibers had good potential for further application in ammonia detection and remote monitoring in real time.