Memisoglu Gorkem, Gulbahar Burhan, Fernandez Bello Ruben
Department of Communications Engineering, University of the Basque Country (UPV/EHU), Plaza Ingeniero Torres Quevedo 1, E-48013 Bilbao, Spain.
Department of Electrical and Electronics Engineering, Ozyegin University, 34794 Istanbul, Turkey.
Micromachines (Basel). 2020 Jan 18;11(1):104. doi: 10.3390/mi11010104.
We demonstrate freely suspended graphene-based nanomechanical membranes (NMMs) as acoustic sensors in the audible frequency range. Simple and low-cost procedures are used to fabricate NMMs with various thicknesses based on graphene layers grown by graphite exfoliation and solution processed graphene oxide. In addition, NMMs are grafted with quantum dots (QDs) for characterizing mass sensitive vibrational properties. Thickness, roughness, deformation, deflection and emissions of NMMs with attached QDs are experimented and analyzed by utilizing atomic force microscopy, Raman spectroscopy, laser induced deflection analyzer and spectrophotometers. Förster resonance energy transfer (FRET) is experimentally achieved between the QDs attached on NMMs and nearby glass surfaces for illustrating acousto-optic utilization in future experimental implementations combining vibrational properties of NMMs with optical emission properties of QDs. This property denoted as vibrating FRET (VFRET) is previously introduced in theoretical studies while important experimental steps are for the first time achieved in this study for future VFRET implementations. The proposed modeling and experimental methodology are promising for future novel applications such as NMM based biosensing, photonics and VFRET based point-of-care (PoC) devices.
我们展示了在可听频率范围内作为声学传感器的自由悬浮石墨烯基纳米机械膜（NMM）。采用简单且低成本的工艺，基于通过石墨剥离生长的石墨烯层和溶液处理的氧化石墨烯制备了具有不同厚度的NMM。此外，NMM接枝有量子点（QD）以表征质量敏感的振动特性。利用原子力显微镜、拉曼光谱、激光诱导偏转分析仪和分光光度计对附着有QD的NMM的厚度、粗糙度、变形、挠度和发射进行了实验和分析。在附着于NMM的QD与附近玻璃表面之间通过实验实现了福斯特共振能量转移（FRET），以说明在未来实验实现中将NMM的振动特性与QD的光发射特性相结合的声光应用。这种特性被称为振动FRET（VFRET），此前在理论研究中已被引入，而本研究首次实现了未来VFRET实现的重要实验步骤。所提出的建模和实验方法对于未来基于NMM的生物传感、光子学和基于VFRET的即时检测（PoC）设备等新型应用具有前景。
