Graphene resonant sensors have shown strong competitiveness with respect to sensitivity and size. To advance the applications of graphene resonant sensors, the damage behaviors of graphene harmonic oscillators after thermal annealing and laser irradiation were investigated by morphology analysis and frequency domain vibration characteristics. The interface stress was proven to be the key factor that directly affected the yield of resonators. The resulting phenomenon could be improved by appropriately controlling the annealing temperature and size of resonators, thereby achieving membrane intactness of up to 96.4%. However, micro-cracks were found on the graphene sheets when continuous wave (CW) laser power was more than 4 mW. Moreover, the fluctuating light energy would also cause mechanical fatigue in addition to the photothermal effect, and the threshold damage power for the sinusoidally modulated laser was merely 2 mW. In this way, based on the amplitude-frequency surface morphology of the graphene resonator, the thermal time constant of the order of a few microseconds was confirmed to evaluate the damage of the graphene oscillator in situ and in real time, which could be further extended for those resonators using other 2D materials.
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http://dx.doi.org/10.3390/nano12152725 | DOI Listing |
Anal Chim Acta
January 2025
The Education Ministry Key Laboratory of Resource Chemistry, Joint International Research Laboratory of Resource Chemistry, Ministry of Education, Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Municipal Education Committee Key Laboratory of Molecular Imaging Probes and Sensors, Shanghai Frontiers Science Center of Biomimetic Catalysis and College of chemistry and materials science, School of Environmental and Geographical Sciences. Shanghai Normal University, Shanghai, 200234, People's Republic of China. Electronic address:
Background: Polycyclic aromatic hydrocarbons (PAHs) are one of the most dangerous persistent organic pollutants in the environment. Due to the discharge of chemical plants and domestic water, the existence of PAHs in sea water and lake water is harmful to human health. A method for rapid detection and removal of PAHs in water needs to be developed.
View Article and Find Full Text PDFJ Phys Chem A
January 2025
Key Lab of Advanced Transducers and Intelligent Control System, Ministry of Education and Shanxi Province, College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan 030024, China.
Plasmon resonance plays an important role in improving the detection of biomolecules, and it is one of the focuses of research to use metal plasmon resonance to achieve fluorescence enhancement and to improve detection sensitivity. However, the problems of nondynamic tuning and fluorescence quenching of metal plasmon resonance need to be solved. Graphene surface plasmon resonance can be dynamically controlled, and the graphene adsorption of fluorescent molecules can avoid fluorescence quenching and greatly improve the fluorescence emission intensity.
View Article and Find Full Text PDFNanotechnology
January 2025
Department of Chemical Engineering , University of Patras, Panepistimioupoli, Rio, GR-26504 Patras, Patra, Periféria Dhitikís Elládh, 26504, GREECE.
This study investigates the enhancement of damping properties in carbon fiber-reinforced polymer (CFRP) composites by incorporating graphene nanoplatelets (GNPs) into the epoxy matrix. Epoxy and CFRP specimens with varying GNP concentrations, were developed and tested through free vibration experiments to measure damping ratios. Additionally, a computational model based on the finite element method (FEM) was developed to simulate the damping behavior of these hybrid nanocomposites.
View Article and Find Full Text PDFNano Lett
January 2025
Institute for Experimental and Applied Physics, University of Regensburg, 93040 Regensburg, Germany.
Understanding and controlling the electronic properties of two-dimensional materials are crucial for their potential applications in nano- and optoelectronics. Monolayer transition metal dichalcogenides have garnered significant interest due to their strong light-matter interaction and extreme sensitivity of the band structure to the presence of photogenerated electron-hole pairs. In this study, we investigate the transient electronic structure of monolayer WS on a graphene substrate after resonant excitation of the A-exciton using time- and angle-resolved photoemission spectroscopy.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Research Group of Organic Synthesis and Catalysis, University of Pannonia, Egyetem u. 10, 8200 Veszprém, Hungary.
In the present study, synthesis, conformational behavior, host-guest complex formation, and electrochemical properties of novel 6-substituted-2-ureido-4-ferrocenylpyrimidines were explored. A comprehensive NMR spectroscopic investigation was carried out to confirm the structure and conformational equilibrium of the ureidopyrimidines through studying the temperature- and concentration dependence of NMR spectra. Low-temperature NMR measurements were used to clarify structural changes inflicted by a 2,6-diaminopyridine guest.
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