Bodenhöfer K, Hierlemann A, Noetzel G, Weimar U, Göpel W
Institute of Physical and Theoretical Chemistry, Center of Interface Analysis and Sensors, University of Tübingen, Auf der Morgenstelle 8, D-72076 Tübingen, Germany.
Anal Chem. 1996 Jul 1;68(13):2210-8. doi: 10.1021/ac9600215.
In this work we investigated different thickness shear mode resonators (TSMRs) with fundamental frequencies of 10 and 30 MHz and surface acoustic wave devices with fundamental frequencies of 80 and 433 MHz. Four aspects were of primary interest in this comparison: noise levels and signal-to-noise ratios (S/N), influence of the polymer film thickness, influence of temperature on the transducer signal before and after coating, and minimum threshold values for monitoring different volatile organic compounds in the environment. We limited our investigations to a temperature range between 298 and 308 K, with 303 K the routine measuring temperature. Analyte concentrations (n-octane, tetrachloroethene) were chosen from the minimum detection limit up to 5000 μg/L. The temperature was found to strongly affect the performance of all the devices. The sorption of the analyte vapors into the polymeric films was demonstrated to be transducer-independent (identical partition coefficients for all the devices). The 30 MHz TSMRs showed very satisfying results in terms of S/N and limits of detection.
在这项工作中，我们研究了基频为10和30 MHz的不同厚度剪切模式谐振器（TSMR）以及基频为80和433 MHz的表面声波器件。在这种比较中，主要关注四个方面：噪声水平和信噪比（S/N）、聚合物膜厚度的影响、温度对涂层前后换能器信号的影响以及监测环境中不同挥发性有机化合物的最小阈值。我们将研究限制在298至308 K的温度范围内，常规测量温度为303 K。分析物浓度（正辛烷、四氯乙烯）的选择范围是从最低检测限到5000 μg/L。发现温度对所有器件的性能有强烈影响。已证明分析物蒸气在聚合物膜中的吸附与换能器无关（所有器件的分配系数相同）。就信噪比和检测限而言，30 MHz的TSMR显示出非常令人满意的结果。
