Spectroscopic and Sensing Devices Research Group (SSDRG), Opto-Electrochemical Sensing Research Team (OEC), National Electronics and Computer Technology Center (NECTEC), Pathum Thani, 12120, Thailand.
School of Engineering, BU-CROCCS, Bangkok University, Pathum Thani, 12120, Thailand.
Sci Rep. 2023 Jul 4;13(1):10799. doi: 10.1038/s41598-023-37795-6.
This paper experimentally demonstrates a crossed reaction of pure and hybrid graphene oxide (GO)/tantalum dioxide (TaO) as a volatile organic compound (VOC) absorber in a guided mode resonance (GMR) sensing platform. The proposed GMR platform has a porous TaO film as the main guiding layer, allowing for more molecular adsorption and enhanced sensitivity. GO is applied on top as an additional VOC absorber to increase the selectivity. The hybrid sensing mechanism is introduced by varying the concentration of the GO aqueous solution. The experimental results show that the pure TaO-GMR has a high tendency to adsorb most of the tested VOC molecules, with the resonance wavelength shifting accordingly to the physical properties of the VOCs (molecular weight, vapor pressure, etc). The largest signal appears in the large molecule such as toluene, and its sensitivity is gradually reduced in the hybrid sensors. At the optimum GO concentration of 3 mg/mL, the hybrid GO/TaO -GMR is more sensitive to methanol, while the pure GO sensor coated with GO at 5 mg/mL is highly selective to ammonia. The sensing mechanisms are verified using the distribution function theory (DFT) to simulate the molecular absorption, along with the measured functional groups measured on the sensor surface by the Fourier transform infrared spectroscopy (FTIR). The crossed reaction of these sensors is further analyzed by means of machine learning, specifically the principal component analysis (PCA) method and decision tree algorithm. The results show that this sensor is a promising candidate for quantitative and qualitative VOCs detection in sensor array platform.
本文通过实验证明了纯氧化石墨烯（GO）/二氧化钽（TaO）和混合氧化石墨烯（GO）/二氧化钽（TaO）在导模共振（GMR）传感平台中作为挥发性有机化合物（VOC）吸收剂的交叉反应。所提出的 GMR 平台具有多孔 TaO 薄膜作为主要导向层，允许更多的分子吸附并提高了灵敏度。GO 被应用于顶部作为额外的 VOC 吸收剂，以提高选择性。通过改变 GO 水溶液的浓度引入了混合传感机制。实验结果表明，纯 TaO-GMR 具有强烈的倾向，吸附大多数测试的 VOC 分子，共振波长相应地根据 VOC 的物理性质（分子量、蒸气压等）发生变化。最大信号出现在甲苯等大分子中，而在混合传感器中其灵敏度逐渐降低。在最佳的 GO 浓度 3 mg/mL 时，混合 GO/TaO-GMR 对甲醇更敏感，而涂有 5 mg/mL GO 的纯 GO 传感器对氨具有高选择性。通过使用分布函数理论（DFT）模拟分子吸收，并通过傅里叶变换红外光谱（FTIR）测量传感器表面的测量官能团来验证传感机制。通过机器学习，特别是主成分分析（PCA）方法和决策树算法，进一步分析了这些传感器的交叉反应。结果表明，该传感器是传感器阵列平台中定量和定性 VOC 检测的有前途的候选者。
