A novel wearable TEA sensor based on PDDA-functionalized graphene/polyaniline composite self-powered by a triboelectric nanogenerator

To improve the sensing performance of the traditional semiconductor sensor towards triethylamine (TEA), the poly(diallyldimethylammonium chloride) (PDDA) has been applied to functionalize the reduced graphene oxide (rGO), which has been further decorated by the polyaniline (PANI) nanocones via an in-situ polymerization method. The existence of PDDA during the synthetic process could efficiently prevent the restacking of rGO and promote the reduction of graphene oxide, which is beneficial for producing uniform PANI nanocones on the rGO sheets and improving the sensitivity to TEA. The sensor fabricated by the PDDA-rGO-PANI has exhibited excellent sensing performance to the TEA with superior sensitivity, stability and selectivity at room temperature. The sensor possesses a perfect linear coefficient of 0.999 from 2 to 100 ppm TEA and an extremely low limit-of-detection (LOD) of 74 ppb. In addition, the sensor has presented an outstanding anti-interference ability against humidity, other interfering gases (ammonia and common VOCs) and even mechanical bending. Finally, a self-powered sensing system containing a homemade triboelectric nanogenerator (TENG), a commercial flexible electrode, a button battery and the integrated circuit LTC3588 has been fabricated. The size of TENG is only 3.5×3.5 cm2 while the sensing system after integrated on a PI membrane is just 2×4 cm2, which makes the sensor a promising potential candidate of wearable sensing to TEA in daily life.