Three-dimensional conductive organic sulfonic acid co-doped bacterial cellulose/polyaniline nanocomposite films for detection of ammonia at room temperature

Polymer sulfonic acid doped polyaniline (PANI) can improve the response to ammonia. An ammonia sensor (BC/PANI-DBSA/PAMPS) with ultrafast, selective and sensitive detecting capability based on bacterial cellulose (BC) film with a three-dimensional nano-network structure is reported. The sensor consists of PANI coated BC nanofiber co-doped with dodecylbenzene sulfonic acid (DBSA) and poly(2-acrylamido-2-methyl-1-propane sulfonic acid) (PAMPS), made by an in situ chemical oxidation polymerization route. The sensing response of the DBSA and PAMPS co-doping PANI composite in the range of 10-150 ppm ammonia vapor was greatly enhanced compared to sole doped composite, and showed high sensing selectivity towards ammonia, with a low detection limit of 200 ppb at mom temperature. More importantly, the sensor display an excellent response (S = 6.1) and rapid response/recovery time (10.2 s/8.6 s) toward 100 ppm ammonia, and still showed excellent sensing capability after up to 60 days. Taken together, this work provides a facile and green approach to fabricate macroscale materials with ultra-fine nanoscale architecture for fast and sensitive gas detection.