International School of Engineering (ISE), Intelligent Control Automation of Process Systems Research Unit, Chulalongkorn University, Bangkok 10330, Thailand.
Biomedical Engineering Program, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand.
Biosensors (Basel). 2023 Jan 9;13(1):114. doi: 10.3390/bios13010114.
In general, volatile organic compounds (VOCs) have a high vapor pressure at room temperature (RT). It has been reported that all humans generate unique VOC profiles in their exhaled breath which can be utilized as biomarkers to diagnose disease conditions. The VOCs available in exhaled human breath are the products of metabolic activity in the body and, therefore, any changes in its control level can be utilized to diagnose specific diseases. More than 1000 VOCs have been identified in exhaled human breath along with the respiratory droplets which provide rich information on overall health conditions. This provides great potential as a biomarker for a disease that can be sampled non-invasively from exhaled breath with breath biopsy. However, it is still a great challenge to develop a quick responsive, highly selective, and sensitive VOC-sensing system. The VOC sensors are usually coated with various sensing materials to achieve target-specific detection and real-time monitoring of the VOC molecules in the exhaled breath. These VOC-sensing materials have been the subject of huge interest and extensive research has been done in developing various sensing tools based on electrochemical, chemoresistive, and optical methods. The target-sensitive material with excellent sensing performance and capturing of the VOC molecules can be achieved by optimizing the materials, methods, and its thickness. This review paper extensively provides a detailed literature survey on various non-biological VOC-sensing materials including metal oxides, polymers, composites, and other novel materials. Furthermore, this review provides the associated limitations of each material and a summary table comparing the performance of various sensing materials to give a better insight to the readers.
一般来说,挥发性有机化合物(VOCs)在室温下具有较高的蒸气压。据报道,所有人类在呼气中都会产生独特的 VOC 谱,可以将其用作诊断疾病的生物标志物。呼气中存在的 VOC 是体内代谢活动的产物,因此可以利用其控制水平的任何变化来诊断特定疾病。在呼气中已鉴定出 1000 多种 VOC 以及呼吸飞沫,这些提供了有关整体健康状况的丰富信息。这为使用呼吸活检从呼气中无创采样的疾病提供了巨大的生物标志物潜力。然而,开发快速响应、高选择性和高灵敏度的 VOC 传感系统仍然是一个巨大的挑战。VOC 传感器通常涂有各种传感材料,以实现对目标特异性检测和对呼气中 VOC 分子的实时监测。这些 VOC 传感材料一直是人们关注的焦点,已经进行了广泛的研究,以基于电化学、化学电阻和光学方法开发各种传感工具。通过优化材料、方法及其厚度,可以实现具有优异传感性能和 VOC 分子捕获能力的目标敏感材料。本文综述广泛提供了各种非生物 VOC 传感材料的详细文献调查,包括金属氧化物、聚合物、复合材料和其他新型材料。此外,本文还提供了每种材料的相关局限性,并比较了各种传感材料的性能总结表,以便读者更好地了解。