Fabrication of Nitroaniline Chemical Sensor Based on Polyaniline Coated Multi-Walled Carbon Nanotubes

This paper reports the fabrication and characterization of polyaniline (PANI) coated multi-walled carbon nanotubes (MWCNTs). The PANI-MWCNTs nanocomposites were prepared by facile and low-temperature polymerization of aniline under acidic conditions. The prepared PANI-MWCNTs nanocomposites were characterized by several techniques to examine the morphological, structural, compositional and scattering properties. The observed TEM images clearly revealed that the PANI is uniformly coated on the surfaces of MWCNTs. The X-ray diffraction (XRD) pattern exhibit diffraction reflections belong to the emeraldine salt form of PANI and characteristics MWCNT peaks which confirmed the formation of PANI-MWCNTs nanocomposite. The Raman-scattering spectra show a band near 1584 cm(-1) due to C=C stretching in the quinoid rings of PANI. Further, the prepared PANI-MWCNTs nanocomposite were used as effective electron mediator to fabricate highly sensitive nitroaniline chemical sensor. The fabricated nitroaniline chemical sensor exhibited a high sensitivity of 2.59 mA.mM(-1).cm(-2), the low detection limit of 1.23 mM and a correlation coefficient of 0.9234. The fabricated sensor also possesses long-term stability. The observed results confirmed that polymer-coated MWCNTs are efficient electron mediators to fabricate highly sensitive and stable chemical sensors.