Singh Sukhwinder, Deb Jyotirmoy, Singh Jatinder Vir, Sarkar Utpal, Sharma Sandeep
Department of Physics, Guru Nanak Dev University, Amritsar, Punjab 143005, India.
Department of Physics, Assam University, Silchar 788011, India.
ACS Appl Mater Interfaces. 2022 May 13. doi: 10.1021/acsami.1c25112.
Volatile organic sulfur compounds (VOSCs) serve not only as biomarkers for dental diseases such as halitosis but also as a tracer for monitoring air quality. Room-temperature selective detection and superior sensitivity against VOSCs at a sub-ppm level has remained a challenging task. Here, we propose a heterostructure-based design using a MoSe/SnO composite for achieving sensitive and selective detection of ethyl mercaptan at room temperature. The composite was synthesized via a facile two-step method. A composite-based device has shown detection down to 1 ppm of ethyl mercaptan over a wider range of relative humidity (40-90%). Notably, the composite has shown adsorption selectivity toward ethyl mercaptan compared to hydrogen sulfide and other reducing or oxidizing analytes. Moreover, a density functional theory (DFT) study has been performed to understand the adsorption selectivity, charge transfer, and modification in the electronic properties after molecule adsorption on the host surface. Simulations predicted the lowest negative adsorption energy for ethyl mercaptan, implying the chemisorption (-142.029 kJ mol) process of adsorption. The device thus-obtained has also shown a stable response even at an extreme relative humidity level of 90%. The obtained results and superior signal-to-noise ratio indicate that a MoSe/SnO-based sensor may be a promising candidate for highly selective and sensitive detection of ethyl mercaptan even below 1 ppm.
挥发性有机硫化合物（VOSCs）不仅可作为口臭等口腔疾病的生物标志物，还可作为监测空气质量的示踪剂。室温下对亚ppm水平的VOSCs进行选择性检测并具有卓越的灵敏度仍然是一项具有挑战性的任务。在此，我们提出一种基于异质结构的设计，使用MoSe/SnO复合材料在室温下实现对乙硫醇的灵敏且选择性检测。该复合材料通过简便的两步法合成。基于该复合材料的器件在较宽的相对湿度范围（40 - 90%）内对乙硫醇的检测下限可达1 ppm。值得注意的是，与硫化氢以及其他还原性或氧化性分析物相比，该复合材料对乙硫醇表现出吸附选择性。此外，还进行了密度泛函理论（DFT）研究，以了解分子吸附在主体表面后的吸附选择性、电荷转移和电子性质的变化。模拟预测乙硫醇的负吸附能最低，这意味着存在化学吸附（-142.029 kJ mol）过程。如此获得的器件即使在90%的极端相对湿度水平下也表现出稳定的响应。所获得的结果以及卓越的信噪比表明，基于MoSe/SnO的传感器可能是用于高选择性和灵敏检测甚至低于1 ppm乙硫醇的有前景的候选者。
