A volatile organic compounds (VOC) sensor based on molecularly imprinted polymer (MIP) modified quartz tuning fork (QTF) has been developed. In this paper, the stability of the modified sensor as a function of the MIP composition, and the temperature effect of the analyte adsorption on the sensing transduction mechanism are evaluated. By mixing MIP and PS together, the stability was improved. A target analyte, o-xylene, was chosen as the VOC model to study the sensor response in a temperature range of 6–40 °C. Langmuir model fitted adsorption isotherms were used for thermodynamic analysis. The changes in the sensitivity of the QTF sensor to temperature rendered different behaviors. For a freshly modified QTF sensor, the adsorption response increased with increasing temperature, while for an aged QTF sensor, the adsorption response decreased with increasing temperature. The results indicated that the enthalpy change of the MIP and PS composition sensing material changes from positive to negative over the course of aging. The characterization of the reaction enabled the definition of sensor calibration conditions and stable sensor performance in field testing conditions.

中文翻译：

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基于石英音叉的挥发性有机物检测传感器的吸附热力学分析

已经开发了一种基于分子印迹聚合物（MIP）改性石英音叉（QTF）的挥发性有机化合物（VOC）传感器。在本文中，评估了作为MIP成分的函数的改进型传感器的稳定性，以及分析物吸附对传感传导机制的温度影响。通过将MIP和PS混合在一起，可以提高稳定性。目标分析物，o选择二甲苯作为VOC模型来研究6–40°C温度范围内的传感器响应。用Langmuir模型拟合的吸附等温线进行热力学分析。QTF传感器对温度的灵敏度变化导致了不同的行为。对于新改良的QTF传感器，吸附响应随温度升高而增加，而对于老化的QTF传感器，吸附响应随温度升高而降低。结果表明，在老化过程中，MIP和PS成分感测材料的焓变从正变为负。反应的表征使得能够定义传感器校准条件，并在现场测试条件下具有稳定的传感器性能。