A SAW-based chemical sensor for detecting sulfur-containing organophosphorus compounds using a two-step self-assembly and molecular imprinting technology.
This paper presents a new effective approach for the sensitive film deposition of surface acoustic wave (SAW) chemical sensors for detecting organophosphorus compounds such as O-ethyl-S-2-diisopropylaminoethyl methylphosphonothiolate (VX) containing sulfur at extremely low concentrations. To improve the adsorptive efficiency, a two-step technology is proposed for the sensitive film preparation on the SAW delay line utilizing gold electrodes. First, mono[6-deoxy-6-[(mercaptodecamethylene)thio]]-β-cyclodextrin is chosen as the sensitive material for VX detection, and a ~2 nm-thick monolayer is formed on the SAW delay line by the binding of Au-S. This material is then analyzed by atomic force microscopy (AFM). Second, the VX molecule is used as the template for molecular imprinting. The template is then removed by washing the delay line with ethanol and distilled water, thereby producing the sensitive and selective material for VX detection. The performance of the developed SAW sensor is evaluated, and results show high sensitivity, low detection limit, and good linearity within the VX concentration of 0.15-5.8 mg/m3. The possible interactions between the film and VX are further discussed.
State Key Laboratory of NBC Protection for Civilian, Research Institute of Chemical Defense, Yangfang, Changping District, Beijing 102205, China. panyong71@sina.com.cn.
Yong
Y
Pan
State Key Laboratory of NBC Protection for Civilian, Research Institute of Chemical Defense, Yangfang, Changping District, Beijing 102205, China. Yangliujinjin@sina.com.
Liu
L
Yang
State Key Laboratory of NBC Protection for Civilian, Research Institute of Chemical Defense, Yangfang, Changping District, Beijing 102205, China. Sdmuta@163.com.
Ning
N
Mu
State Key Laboratory of NBC Protection for Civilian, Research Institute of Chemical Defense, Yangfang, Changping District, Beijing 102205, China. Shaoshengyu@163.com.
Shengyu
S
Shao
Institute of Acoustic, Chinese Academy of Science, Zhongguancun Street, Haidian District, Beijing 100080, China. Wangwenwq@mail.ioa.ac.cn.
Wen
W
Wang
Institute of Acoustic, Chinese Academy of Science, Zhongguancun Street, Haidian District, Beijing 100080, China. Xiexiao08@mails.ucas.ac.cn.
Xiao
X
Xie
Institute of Acoustic, Chinese Academy of Science, Zhongguancun Street, Haidian District, Beijing 100080, China.
Shitang
S
He
D004566:Electrodes; D006046:Gold; D018625:Microscopy, Atomic Force; D054802:Molecular Imprinting; D015336:Molecular Probe Techniques / Q000295:instrumentation; D009946:Organothiophosphorus Compounds / Q000032:analysis* / Q000737:chemistry*; D013455:Sulfur / Q000737:chemistry
D009946:Organothiophosphorus Compounds; D013455:Sulfur; D006046:Gold