Snitka Valentinas, Batiuskaite Danute, Bruzaite Ingrida, Lafont Ugo, Butenko Yuriy, Semprimoschnig Christopher
Research Center for Microsystems and Nanotechnology, Kaunas University of Technology, Studentu 65, Kaunas, Lithuania.
Department of Biology, Faculty of Natural Sciences, Vytautas Magnus University, 58 K.Donelaicio str., 44248 Kaunas, Lithuania.
CEAS Space J. 2021;13(3):509-520. doi: 10.1007/s12567-021-00356-6. Epub 2021 Mar 8.
The detection of molecular traces in the environment is a technical problem that is critical in pollutant control procedures at all stages of spacecraft assembly, in space flight, as well as in other technological processes such as food production, medical diagnostics, environmental control, warfare. However, in the aerospace industry, it is necessary to detect molecular traces of contaminants with extreme sensitivity, as even concentrations as low as part-per-billion (ppb) can be critical during long missions. The high sensitivity of the Volatile Organic Compounds (VOCs) detection within the air can be a challenge because of the poor affinity of VOC's to the metal surface of the sensor substrate. In this work, we present a surface-enhanced Raman scattering (SERS) spectroscopy technique as a highly sensitive and selective molecular sensor for gas trace detection not sensitive to molecules adsorbtion on sensing element. The developed hybrid SERS platform for molecular trace detection is supported by the hybrid nanoplasmonic porous silicon membrane in conjunction with micropump to achieve the trace level detection of VOCs in the environment. The combination of silicon membrane, made by electrochemical etching of the microchannels in the silicon chip, with chemical deposition of the silver nanoparticles inside the channels, produce a porous Ag nanoparticles membrane with a high density of plasmonic nanostructures ("hot spots"). The micropump integrated with the SERS sensor, pump the air with VOC's molecules through the plasmonic membrane "hot spots" to increase the probability of interaction of VOC's molecules with SERS substrate and to increase the enhancement factor. The sensor chip structure was designed, gas flow in the sensor was simulated, and the sensor was fabricated using 3D printing. The limit of detection of hydrazine with concentration level 10 M from solution and the vapor phase 0.1 ppm was demonstrated. The anisole vapors with concentration 0.5 ppb spectra in the air were recorded. Our results demonstrate that plasmonic membrane can be used as a high enhancement factor SERS sensor for many pollutants molecules detection with the nanomolar sensitivity and can be applied in the design of sensors for space applications, environment control, biomedical diagnostic.
The online version contains supplementary material available at 10.1007/s12567-021-00356-6.
在环境中检测分子痕迹是一个技术难题，这在航天器组装的各个阶段、太空飞行以及其他技术过程（如食品生产、医学诊断、环境控制、战争）的污染物控制程序中都至关重要。然而，在航空航天工业中，必须以极高的灵敏度检测污染物的分子痕迹，因为即使低至十亿分之一（ppb）的浓度在长时间任务中也可能至关重要。由于挥发性有机化合物（VOCs）与传感器基板的金属表面亲和力较差，因此检测空气中的VOCs的高灵敏度可能是一项挑战。在这项工作中，我们提出了一种表面增强拉曼散射（SERS）光谱技术，作为一种对传感元件上分子吸附不敏感的用于气体痕量检测的高灵敏度和选择性分子传感器。用于分子痕量检测的开发的混合SERS平台由混合纳米等离子体多孔硅膜与微型泵结合支持，以实现环境中VOCs的痕量水平检测。通过对硅芯片中的微通道进行电化学蚀刻制成的硅膜与通道内银纳米颗粒的化学沉积相结合，产生了具有高密度等离子体纳米结构（“热点”）的多孔银纳米颗粒膜。与SERS传感器集成的微型泵，将含有VOC分子的空气泵过等离子体膜“热点”，以增加VOC分子与SERS基板相互作用的概率并增加增强因子。设计了传感器芯片结构，模拟了传感器中的气流，并使用3D打印制造了传感器。证明了从溶液中检测浓度为10 M的肼以及气相中检测浓度为0.1 ppm的检测限。记录了空气中浓度为0.5 ppb的苯甲醚蒸气光谱。我们的结果表明，等离子体膜可以用作具有纳摩尔灵敏度的用于检测许多污染物分子高增强因子SERS传感器，并可应用于空间应用、环境控制、生物医学诊断的传感器设计。
在线版本包含可在10.1007/s12567-021-00356-6获取的补充材料。
