Tan Zheng, Wang Jin, Xu Li, Zheng Qijun, Han Lingfei, Wang Chen, Liao Xuewei
College of Chemistry and Materials Science and Analytical & Testing Center, Nanjing Normal University, Nanjing 210023, China.
Department of Pharmaceutical Analysis, China Pharmaceutical University, Nanjing 211198, China.
ACS Sens. 2023 Feb 24;8(2):867-874. doi: 10.1021/acssensors.2c02572. Epub 2023 Feb 1.
Developing highly efficient gas sensors with excellent performance for rapid and sensitive detection of volatile organic compounds (VOCs) is of critical importance for the protection of human health, ecological environment, and other factors. Here, a robust gas sensor based on Raman technology was constructed by an grown 2D covalent organic framework (COF) on Au nanoparticles' surface in the microchannel. Dual enhancement effects are included for the as-prepared microfluidic sensor. First, acting as a gas confinement chamber, the 2D COF could effectively capture gas molecules with high adsorption capacity and fast adsorption kinetics, resulting in VOCs' preconcentration at a high level in the COF layer. At the same time, after being stacked in the microchannel, abundant hot spots were generated among the nanogaps of Au@COF NPs. The local surface plasmon resonance effect could effectively enhance the Raman intensity. Both factors contribute to the improved detection sensitivity of VOCs. As a demonstration, several representative VOCs with different functional groups were tested. The resultant Raman spectra were subjected to the statistical principal component analysis. Varied VOCs can be successfully detected with a detection limit as low as ppb level and distinguished with 95% confidence interval. The present microfluidic platform provides a simple, sensitive, and fast method for VOCs' sensing and distinguishing, which is expected to hold potential applications in the fields of health, agricultural, and environmental research.
开发具有优异性能的高效气体传感器，用于快速、灵敏地检测挥发性有机化合物（VOCs），对于保护人类健康、生态环境及其他因素至关重要。在此，通过在微通道中Au纳米颗粒表面生长二维共价有机框架（COF）构建了一种基于拉曼技术的坚固气体传感器。所制备的微流控传感器具有双重增强效应。首先，二维COF作为气体限制腔，能够以高吸附容量和快速吸附动力学有效地捕获气体分子，从而在COF层中实现VOCs的高水平预浓缩。同时，在微通道中堆叠后，Au@COF NPs的纳米间隙之间产生了大量热点。局部表面等离子体共振效应可有效增强拉曼强度。这两个因素都有助于提高VOCs的检测灵敏度。作为演示，测试了几种具有不同官能团的代表性VOCs。所得拉曼光谱进行了统计主成分分析。能够成功检测出各种VOCs，检测限低至ppb水平，并以95%的置信区间进行区分。本微流控平台为VOCs的传感和区分提供了一种简单、灵敏且快速的方法，有望在健康、农业和环境研究领域具有潜在应用。
