Development of a Quartz Crystal Microbalance Sensor Modified by Nano-Structured Polyaniline for Detecting the Plasticizer in Gaseous State

A quartz crystal microbalance (QCM) modified by a film of nano-structured polyaniline (nano-PANI) is developed as a gas sensor for detecting the presence of the plasticizer, such as dibutyl phthalate (DBP) in the ambient. Nano-PANI is prepared using a non-template method and the films are deposited using physical coating method. Scanning electron microscopy is used to characterize the nano-PANI film. The sensor response towards DBP is tested in a sealed gas chamber. The QCM resonant frequency shift is measured due to the absorption of DBP with different concentration ranging from 0.04 to 1.2 ppm. The experiment results show that the variation of the frequency is a linear function of DBP concentration and the sensitivity up to 54 Hz/ppm could be achieved by using the researched nano-PANI on QCM. To investigate the selectivity, the potential interfering analytes such as acetone, ethanol, acetaldehyde and formaldehyde are tested. And the mechanism hypothesis of the nano-PANI sensitive to the plasticizer is analyzed