College of Science, Northeastern University, Shenyang 110819, China.
ACS Sens. 2023 Sep 22;8(9):3487-3497. doi: 10.1021/acssensors.3c01061. Epub 2023 Aug 29.
The accurate, sensitive, and selective on-site screening of volatile aldehyde biomarkers for lung cancer is of utmost significance for preclinical cancer diagnosis and treatment. Applying surface-enhanced Raman scattering (SERS) for gas sensing remains difficult due to the small Raman cross section of most gaseous molecules and interference from other components in exhaled breath. Using an Au asymmetrically coated TiO nanochannel membrane (Au/TiO NM) as the substrate, a ZIF-8-covered Au/TiO NM SERS sensing substrate is designed for the detection of exhaled volatile organic compounds (VOCs). Au/TiO NM provides uniformly amplified Raman signals for trace measurements in this design. Importantly, the interfacial nanocavities between Au nanoparticles (NPs) and metal-organic frameworks (MOFs) served as gaseous confinement cavities, which is the key to enhancing the capture and adsorption ability toward gaseous analytes. Both ends of the membrane are left open, allowing gas molecules to pass through. This facilitates the diffusion of gaseous molecules and efficient capture of the target analyte. Using benzaldehyde as a typical gas marker model of lung cancer, the Schiff base reaction with a Raman-active probe molecule 4-aminothiophene (4-ATP) pregrafted on Au NPs enabled trace and multicomponent detection. Moreover, the combination of machine learning (ML) and Raman spectroscopy eliminates subjective assessments of gaseous aldehyde species with the use of a single feature peak, allowing for more accurate identification. This membrane sensing device offers a promising design for the development of a desktop SERS analysis system for lung cancer point-of-care testing (POCT).
准确、灵敏、选择性地现场筛选肺癌挥发性醛类生物标志物，对于临床前癌症诊断和治疗至关重要。由于大多数气态分子的拉曼截面较小，以及呼气中其他成分的干扰，应用表面增强 Raman 散射（SERS）进行气体传感仍然具有挑战性。本研究采用 Au 不对称涂覆的 TiO 纳米通道膜（Au/TiO NM）作为基底，设计了一种 ZIF-8 覆盖的 Au/TiO NM SERS 传感基底，用于检测呼出的挥发性有机化合物（VOCs）。在该设计中，Au/TiO NM 为痕量测量提供了均匀放大的 Raman 信号。重要的是，Au 纳米粒子（NPs）和金属有机骨架（MOFs）之间的界面纳米腔作为气态限制腔，这是增强对气态分析物的捕获和吸附能力的关键。膜的两端保持开放，允许气体分子通过。这促进了气态分子的扩散和目标分析物的有效捕获。本研究以苯甲醛作为肺癌的典型气体标志物模型，利用拉曼活性探针分子 4-氨基噻吩（4-ATP）与 Schiff 碱的反应，实现了痕量和多组分检测。此外，机器学习（ML）和 Raman 光谱的结合消除了使用单一特征峰对气态醛类物质的主观评估，从而实现更准确的识别。这种膜传感装置为开发用于肺癌即时检测（POCT）的桌面 SERS 分析系统提供了有前途的设计。
