Related Experiment Video
Updated: Jan 18, 2026

Covalent Attachment of Single Molecules for AFM-based Force Spectroscopy
Published on: March 16, 2020
Analytical application of poly{methyl[3-(2-hydroxy-3,4-difluoro)phenyl]propyl siloxane} as a QCM coating for DMMP
Wei He1, Zhongxiang Liu, Xiaosong Du
1State Key Lab of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, PR China. hewei999@vip.sina.com
Abstract:
A new material-poly{methyl[3-(2-hydroxy-3,4-difluoro)phenyl]propyl siloxane}(PMDFPS) sensitive to toxic organophosphate vapor was synthesized with 2,3-difluorophenol, allyl bromide and poly (methyl hydrosiloxane) as raw materials, via O-alkylation, Claisen rearrange reaction and hydrosilylation reaction. This novel material was then coated on a quartz crystal microbalance (QCM) to investigate its gas sensitive properties to the nerve agent simulant dimethyl methylphosphonate (DMMP) vapor, as well as known interfering vapors. When tested with competing vapors, the sensor was more than 10 times sensitive to DMMP than to other interfering vapors. Thus, high selectivity of poly{methyl[3-(2-hydroxy-3,4-difluoro)phenyl]propyl siloxane} to DMMP was demonstrated. The poly{methyl[3-(2-hydroxy-3,4-difluoro)phenyl]propyl siloxane}-QCM sensor responded linearly to DMMP vapor with a slope of 14 Hz/ppm in the 1-50 ppm range with a detection limit of 0.21 ppm (S/N=3).

