Volatile organic compounds (VOCs) are major environmental pollutants. Exposure to VOCs has been associated with adverse health outcomes. The monitoring of hazardous VOCs is a vital step towards identifying their presence and preventing the risk of acute or chronic exposure and polluting the environment. One of the challenges associated with monitoring VOCs is selectivity of the sensor. Microfluidic gas sensors offer selective and sensitive detection capabilities that have been recently applied for detection of VOCs. In this study, we achieve improved selectivity for detection of a range of VOCs by adding micro- and nanofeatures to the microchannel of microfluidic gas sensors. First, microfeatures are embedded into the microchannel and their geometries are optimized using Taguchi design of experiment method. In the next step the microfeatures embedded microchannel is coated with graphene oxide, to increase the surface to volume ratio by introducing nanofeatures to the surfaces. The nano- and microfeatures are characterized by SEM, XPS, and water contact angle measurement. Finally, the changes in the sensor response are compared to plain microfluidic gas sensor, the results show an average of 64.4% and 120.9% improvement in the selectivity of the sensor with microfeatures and both nano- and microfeatures, respectively

挥发性有机化合物（VOCs）是主要的环境污染物。接触 VOCs 与不良健康结果有关。监测有害 VOC 是识别其存在和防止急性或慢性暴露风险和污染环境的重要一步。与监测 VOC 相关的挑战之一是传感器的选择性。微流体气体传感器提供选择性和灵敏的检测能力，最近已应用于检测 VOC。在这项研究中，我们通过在微流体气体传感器的微通道中添加微米和纳米特征来提高检测一系列 VOC 的选择性。首先，将微观特征嵌入到微通道中，并使用田口设计的实验方法优化它们的几何形状。在下一步中，嵌入微特征的微通道涂有氧化石墨烯，通过将纳米特征引入表面来增加表面体积比。纳米和微观特征通过 SEM、XPS 和水接触角测量来表征。最后，将传感器响应的变化与普通微流控气体传感器进行比较，结果表明具有微特征和纳米特征和微观特征的传感器的选择性分别平均提高了 64.4% 和 120.9%