Novel highly-integrated mems based solid state detectors for analytical gas chromatography

作者：Larin Alexander; Womble Phillip C; Dobrokhotov Vladimir^*

来源：Sensors and Actuators B: Chemical , 2018, 256: 1057-1068.

DOI：10.1016/j.snb.2017.10.046

• Integrated sensor
• Analytical chromatography
• MEMS
• Thin films
• Nanoparticles

In this work, a novel detector of gaseous analytes for monitoring of low levels of BTEX (benzene, toluene, ethylbenzene and o-xylene) is discussed. The detector is based on SnO2 thin (30 nm) films functionalized with gold-palladium (9:1 molar ratio) bimetal nanoparticles. The detector consists of four independent sensing elements thermally activated by an internal heater. The performance of Au/Pd@SnO2 sensing elements was evaluated in comparison with some other gas sensitive materials, such as: pure SnO2, SnO2 decorated with gold (Au), and SnO2 decorated with palladium (Pd) nanoparticles. The superiority of the gas sensing performance of the Au/Pd@SnO2 nanocomposite structure was demonstrated based on its response to low concentrations (12.5-500 ppb) of benzene or toluene. A more complex analysis of gaseous mixtures with different concentrations (0.3-20 ppb) of BTEX mixture was accomplished by incorporating the novel detector into the portable gas chromatograph (GC) PAC R1120. High sensitivity of the detector in combination with fast response and recovery time allowed us to obtain fine gas chromatograms and to perform a complete analysis of a gas sample in less than 11 min. Ultra-low concentrations of BTEX components at sub-ppb level (0.3 ppb) were identified and detected by the GC analysis. Besides the experimental data, the theoretical validation of the detectors high performance was provided based on high catalytic activity of Au/Pd nanoparticles and electronic interaction of bimetal nanoclusters with SnO2 support.

• 出版日期2018-3