Highly sensitive single-walled carbon nanotube/polypyrrole/phenylalanine core-shell nanorods for ammonia gas sensing

In this study, core-shell nanorod composites with a single-walled carbon nanotube (SWCNT) in the core and polypyrrole (PPy)/phenylalanine (PA) shells, SWCNT@PPy@PA, with an average diameter of 80 nm and length of 1-5 μm were successfully synthesized via a simple one-pot emulsion polymerization method. The obtained nanorod composites exhibited not only high conductivity but also high selectivity and sensitivity to ammonia gas. The SWCNT@PPy@PA core-shell nanorod-based sensors showed reliable detection at a concentration of 100 ppb even at room temperature and have the potential to be practically applied to gas sensors. Core-shell nanorod composites with a SWCNT in core and PPy/PA shells, SWCNT@PPy@PA, for 100 ppb ammonia gas sensing.