This work designs the synthesis of a novel amino morpholine schiff base functionalized calix[4]arene cage (SCC), its deposition onto Quartz Crystal Microbalance (QCM) crystal surface, and usage for the selective detecting of formaldehyde (HCHO). The SCC modified QCM sensor has been characterized by contact angle measurements and microscopy images. Initial experiments revealed that the frequency response decreased significantly which means that there was a good interaction between the SCC molecules and HCHO. The proposed sensor exhibited a linear response towards HCHO in different concentrations ranging from 1.85 to 9.25 ppm, having the high sensitivity (S) and low limit of detection (LOD) being 18.324 Hz/ppm and 0.67 ppm, respectively. Furthermore, the adsorption behavior and mechanism of HCHO onto the QCM sensor were investigated for this sensing system and the adsorption data exhibited a good correlation with the Freundlich and Langmuir-Freundlich adsorption models in terms of the regression coefficient. The QCM sensor showed outstanding selective performance to HCHO among %97 RH and some a number of interfering volatile organic compounds (VOCs) such as chloroform, dichloromethane, acetone, n-hexane, methanol, xylene, and ammonia. Thus, real-time, sensitive, selective and effective recognition of HCHO by the sensor can be explained some adsorption mechanisms such as size-fit concept, three-dimensional structures of molecules and interaction between moieties of the sensible film layer and analyte molecules such as hydrogen bonding interactions.

中文翻译：

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一种新颖的基于杯[4]芳烃的QCM传感器，可在室温下对甲醛进行灵敏，选择性和高性能的检测。

这项工作设计了一种新型的氨基吗啉席夫碱功能化杯[4]芳烃笼（SCC）的合成，将其沉积在石英微天平（QCM）晶体表面上，并用于选择性检测甲醛（HCHO）。SCC修改过的QCM传感器的特征在于接触角测量和显微镜图像。最初的实验表明，频率响应显着降低，这意味着SCC分子与HCHO之间存在良好的相互作用。所提出的传感器在1.85至9.25 ppm的不同浓度下对HCHO表现出线性响应，其高灵敏度（S）和低检测限（LOD）分别为18.324 Hz / ppm和0.67 ppm。此外，在该传感系统上研究了HCHO在QCM传感器上的吸附行为和机理，并且在回归系数方面，吸附数据与Freundlich和Langmuir-Freundlich吸附模型表现出良好的相关性。QCM传感器在％97 RH和一些干扰性挥发性有机化合物（VOC）（例如氯仿，二氯甲烷，丙酮，正己烷，甲醇，二甲苯和氨）中显示出对HCHO的出色选择性。因此，可以解释传感器对HCHO的实时，灵敏，选择性和有效识别，这可以解释一些吸附机制，例如尺寸拟合概念，分子的三维结构以及敏感膜层的部分与分析物分子之间的相互作用，例如氢键相互作用。