Nanothin Polyaniline Film for Highly Sensitive Chemiresistive Gas Sensing

Abstract

This study developed a facile technique for site-specific synthesis of nanometer-thick polyaniline (PANI) film for fabrication of field-effect transistor/chemiresistor sensors. The nanothin film had a thickness of 9-20 nm and was of carpet-like morphology offering a highly accessible surface geometry that enhanced gas adsorption and promoted surface reaction/interaction. When applied for sensing of ammonia (NH 3 ) and nitrogen dioxide (NO 2 ), the performance of the nanothin film device was comparable to that of a 1-dimensional (1-D) nanostructure, with a great advantage in ease of processing. Sensing mechanism study indicated electrostatic gating as the dominating mode of sensing.

Potassium Iodide-Functionalized Polyaniline Nanothin Film Chemiresistor for Ultrasensitive Ozone Gas Sensing

“…The OTS-silanized silicon dioxide surface became highly hydrophobic after the silanization treatment, and attracted aniline monomer to accumulate on. The hydrophobic silicon dioxide surface helped to promote lateral film growth during electropolymerization [ 10 , 11 ], and was a key to realizing a nanothin film structure.…”

“…The conductivity of PANI depends strongly on its oxidative state, which allows this polymer to react with species such as NH 3 , NO 2 , and H 2 . We previously reported the synthesis and characterization of nanothin film of PANI and its use for the detection of gases such as NO 2 , NH 3 , formaldehyde, and CO 2 [ 9 , 10 , 11 ]. The nanothin film sensor showed outstanding sensing performance that was comparable to that of the one-dimensional nanostructure and offered advantages in fabrication simplicity and post-synthesis functionalization [ 9 , 11 ].…”

Chemiresistive polyaniline-based gas sensors: A mini review

“…Srinives et al [72] fabricated a PANI nano-thin film chemiresistor sensor using a potentiostatic techniques on a n-octadecyltrichlorosilane [OTS] pretreated microelectrode. The sensing performance of these films was tested by M a n u s c r i p t exposing them to NH 3 and NO 2 gases with encouraging results (sensitivity 21%/ppm for NH 3 and 3760%/ppm for NO 2 ) and good reproducibility.…”

Ammonia gas sensors based on In2O3/PANI hetero-nanofibers operating at room temperature

“…The absorption of NH 3 caused the deprotonation of the N–H + site of the emeraldine salt, leading to a significantly increased resistance [37–38]. When this reaction reached equilibrium in NH 3 atmosphere, the resistance of the PANI-based sensor maintained a constant value.…”