Surface modified polysiloxane a sensitive coatings for QCM sensors

A quartz crystal microbalance (QCM) gas sensor with polysiloxane sensing film was fabricated for detection of dimethyl methyl phosphonate (DMMP), the simulant of chemical warfare agents (CWAs). Poly(methyl-3,3,3-trifluoropropylsiloxane) (PMTFPS) was oxygen plasma treated and then grafted with sulfosalicylic acid (SSA). The resultant SSA modified PMTFPS (SMP) was drop-coated on the electrode of QCM. Compared with the PMTFPS-QCM and SSA-QCM sensors, the sensitivity of SMP-QCM sensor was much higher. However, the SMP films showed less resistance to humidity variations. The selectivity of SMP-QCM sensor to DMMP was also investigated, and better results was showed out after SSA grafted.