This work focuses on the development of nanoparticle-based layer-by-layer (LbL) coatings for enhancing the detection sensitivity and selectivity of volatile organic compounds (VOCs) using on-chip mid-infrared (MIR) waveguides (WGs). First, we demonstrate construction of conformal coatings of polymer/mesoporous silica nanoparticles (MSNs) on the surface of Si-based WGs using the LbL technique and evaluate the coating deposition conditions, such as pH and substrate withdrawal speed, on the thickness and homogeneity of the assemblies. We then use the modified WGs to achieve enhanced sensitivity and selectivity of polar organic compounds, such as ethanol, versus non-polar ones, such as methane, in the MIR region. In addition, using density functional theory calculations, we show that such an improvement in sensing performance is achieved due to preferential adsorption of ethanol molecules within MSNs in the vicinity of the WG evanescent field.

中文翻译：

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利用介孔二氧化硅纳米粒子的表面功能化，以增强E逝场中红外波导气体传感

这项工作的重点是开发基于纳米颗粒的逐层（LbL）涂层，以提高使用片上中红外（MIR）波导（WG）的挥发性有机化合物（VOC）的检测灵敏度和选择性。首先，我们演示了使用LbL技术在硅基WG的表面上构建聚合物/介孔二氧化硅纳米颗粒（MSNs）的保形涂层的方法，并评估了涂层的沉积条件，例如pH值和基材撤出速度，涂层厚度和均质性。程序集。然后，我们使用修饰的WG来实现MIR区域中极性有机化合物（例如乙醇）与非极性化合物（例如甲烷）的灵敏度和选择性的提高。此外，使用密度泛函理论计算，