Article
Mechanics
Matthew Bross, Sven Scharnowski, Christian J. Kaehler
Summary: Studies have shown that in compressible turbulent boundary layer flows, the frequencies of superstructures have slightly longer streamwise wavelengths, and there is a distinct increase in the spanwise spacing of superstructures in supersonic cases compared to subsonic and transonic turbulent boundary layers.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Materials Science, Multidisciplinary
Ida Tyschenko, Fedor Tikhonenko, Anton Gutakovskii, Vladimir Vdovin, Konstantin Rudenko, Vladimir Popov
Summary: In this study, high-resistance silicon layers were formed by CO+ ion implantation and subsequent annealing on silicon substrates. The structural and electric properties of the ion-implanted layers were investigated. The results showed the formation of 3C-SiC and 6H-SiC nanocrystals in the ion-implanted layers and the positive charge compensation in the buried SiO2 layer of a silicon-on-insulator structure. The origin of these results was discussed.
Article
Chemistry, Physical
Pengyu Zang, Yaqian Du, Chenghao Yu, Dan Yang, Shili Gai, Lili Feng, Shikai Liu, Piaoping Yang, Jun Lin
Summary: The newly developed thermoelectric dynamic therapy (TEDT) improves the antitumor efficacy by solving the limitations of overexpression of heat shock proteins (HSPs) in tumor cells during photothermal therapy (PTT). A photothermal-driven TEDT strategy based on Ag-Ag2S nanoparticles was proposed, which integrates Ag2S with Ag+ vacancies (V-Ag) and Ag in a Janus structure. The optimized band structure and thermoelectric properties of Ag2S, along with additional electrons from Ag, enhance the PTT effect and facilitate electron-hole migration, thereby enhancing the TEDT effect.
CHEMISTRY OF MATERIALS
(2023)
Article
Computer Science, Information Systems
Jordan Planillo, Fabio Alves
Summary: Graphene, with its useful properties, has the potential to revolutionize modern electronic devices. This study demonstrates that commercially available graphene, prepared through chemical vapor deposition and processed with photolithography, retains its resilience and exhibits different electrical properties depending on the substrate material. These findings offer a cost-effective means for producing large-scale graphene devices for low to moderate mobility applications and monolithic graphene electronics.
Article
Chemistry, Physical
Lionel Simonot, Florian Chabanais, Sophie Rousselet, Frederic Pailloux, Sophie Camelio, David Babonneau
Summary: Metal nanostructures on a dielectric substrate exhibit unique plasmonic properties dependent on their morphologies. Modifications induced by ultra-low-energy ion-beam bombardment near sputtering threshold allow for controlled changes to the structures and optical properties. The preferential sputtering of smaller particles and erosion of larger ones can tune the plasmonic dichroism of self-organized assemblies, leading to the formation of isolated tiny particles with desired properties.
APPLIED SURFACE SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Naihao Chiang, Leonardo Scarabelli, Gail A. Vinnacombe-Willson, Luis A. Perez, Camilla Dore, Agustin Mihi, Steven J. Jonas, Paul S. Weiss
Summary: Micro- and nanoscale patterned monolayers of plasmonic nanoparticles were fabricated by leveraging chemical interactions and self-assembly techniques. The nanoparticle chemical lift-off lithography (NP-CLL) provides an economical and scalable strategy for the fabrication of functional plasmonic materials.
ACS MATERIALS LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Xiaohua Wang, Chengyun Zhang, Xilin Zhou, Zhengkun Fu, Lei Yan, Jinping Li, Zhenglong Zhang, Hairong Zheng
Summary: Noble metal nanostructures generate strong surface plasmon resonance in the visible light region, which can promote chemical reactions and serve as photocatalytic materials. The catalytic efficiency and stability of Ag/Au nanoislands and Ag NIs/Au film composite systems were greatly improved compared to Ag NIs. The metal nanoislands also generate localized heat at low temperatures, enabling the transition of NaYF4:Eu3+ to Y2O3:Eu3+ and ensuring the relative stability of the constructed complex.
Article
Materials Science, Multidisciplinary
Haibo Hu, Junhua Gao, Wan Wang, Shiwei Tang, Lei Zhou, Qiong He, Haichen Wu, Xiaoying Zheng, Xiaoyun Li, Xiuhong Li, Alexander A. Rogachev, Hongtao Cao
Summary: In this study, a closed plasmonic perfect absorber with ultrathin multi-scale silver nanostructures in SiO2 matrix was fabricated through direct self-organization growth. The designed microstructures achieved a high absorptance across a wide wavelength range and a high visible absorptance.
APPLIED MATERIALS TODAY
(2022)
Article
Chemistry, Physical
Mengyan Cao, Xiujian Zhao, Xiao Gong
Summary: In this work, stable Sb3+ and Bi3+ codoped Cs2ZrCl6 microcrystals were prepared on a large scale for highly efficient white light emission using ionic liquids. The dual emissions originate from the associated self-trapped excitons of the [SbCl6](3-) and [BiCl6](3-) octahedra. The method allows for facile synthesis of large batches of microcrystalline powders and shows potential for future applications in the lighting field.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Yuhan Kong, Gongguo Zhang, Chunyu Wang, Yanyun Ma, Yiqun Zheng
Summary: In this study, Au-Ag Janus nanoparticles (JNPs) with tunable sizes were successfully synthesized, exhibiting multiple plasmonic absorptions. Doping the surface of Au seeds with Pt/Ag atoms introduced lattice strain, crucial for facilitating the anisotropic deposition of Ag. The resulting Au-Ag Janus nanoparticles exhibited more plasmonic absorption peaks compared to core-shell counterparts, showing enhanced catalytic properties.
Article
Nanoscience & Nanotechnology
Adriaan J. Taal, Jake Rabinowitz, Kenneth L. Shepard
Summary: Mr-EBL is established as the highest throughput negative tone electron-beam-sensitive resist, with the ability to fabricate high-resolution nanometer-scale devices in a ten minute EBL process. Optimized processing conditions result in 3x faster write speeds compared to other materials, and the resist demonstrates robust negative etch mask properties with high aspect ratio silicon trenches and near-vertical sidewalls.
Article
Chemistry, Multidisciplinary
Catherine Sadatnajafi, Eugeniu Balaur, Brian Abbey
Summary: Optical metamaterials enable precise control of light at the nanoscale, attracting interest in various fields such as chemical sensing and photovoltaics. Plasmonic color filters can be used for direct optical imaging and characterization of ion implantation in thin films, providing valuable insights for electronic applications.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Jianxun Liu, Hao Zeng, Ming Cheng, Zhenming Wang, Jiawei Wang, Mengjia Cen, Dan Luo, Arri Priimagi, Yan Jun Liu
Summary: The study introduces a photoelastic metasurface that achieves all-optical and reversible resonance tuning in the near infrared range, with an ultra-large spectral tuning range of 245 nm. This technology has great potential for tunable and reconfigurable photonic devices.
MATERIALS HORIZONS
(2022)
Article
Chemistry, Multidisciplinary
Felix Junge, Manuel Auge, Zviadi Zarkua, Hans Hofsaess
Summary: This paper investigates the effectiveness of ultra-low-energy ion implantation for defect engineering in graphene. Scanning Kelvin Probe Microscopy (SKPM) and Raman spectroscopy were used to analyze the samples implanted with boron (B) and helium (He) ions. The results show successful creation of doped and non-doped regions using electrostatic masks, and the feasibility of controllable doping. Raman measurements reveal different damage levels in graphene caused by ion implantation at different energies. Ion implantation simulations were also conducted to evaluate the damage formation.
Review
Chemistry, Multidisciplinary
David Vila-Liarte, Nicholas A. Kotov, Luis M. Liz-Marzan
Summary: The acquisition of strong chiroptical activity has revolutionized the field of plasmonics, enabling new light-matter interactions. Self-assembly of achiral nanoparticles into optically active materials simplifies engineering of chiral geometries and allows for control of structure-optical activity relationships in nanostructures. Chiral structures like helical assemblies and patterned substrates are reviewed as platforms for chiral sensing, with future potential for incorporating semiconductor emitters into plasmonic systems to generate circularly polarized photoluminescence.
Review
Chemistry, Multidisciplinary
Rebeca Moldovan, Bogdan-Cezar Iacob, Cosmin Farcau, Ede Bodoki, Radu Oprean
Summary: Organochlorine pesticides (OCPs) are highly lipophilic chemicals that are being phased out globally due to their persistent nature and detrimental effects on human health and the environment. Traditional separation techniques like gas chromatography are accurate but expensive and time-consuming, prompting researchers to seek faster and more cost-effective alternatives for detection and quantification of OCPs.
Review
Chemistry, Analytical
Rebeca Moldovan, Elizaveta Vereshchagina, Karolina Milenko, Bogdan-Cezar Iacob, Andreea Elena Bodoki, Alexandra Falamas, Nicoleta Tosa, Cristina M. Muntean, Cosmin Farca, Ede Bodoki
Summary: The discovery of surface enhanced Raman scattering (SERS) from an electrochemical (EC)-SERS experiment is a historic breakthrough that has led to the development of Raman spectroelectrochemistry (SEC) as a common characterization tool. Recent studies have shown that EC-SERS sensors have great potential to be used as miniaturized devices for point-of-need (PON) analyses, and they can revolutionize fields such as quality control, diagnosis, and environmental and food safety. Raman spectroelectrochemistry has become a promising alternative to conventional analytical methods and has attracted increasing interest from researchers.
ANALYTICA CHIMICA ACTA
(2022)
Article
Chemistry, Physical
Cosmin Farcau
Summary: This study demonstrates that silver films deposited over regular arrays of polystyrene colloids, known as AgFoN, can function as a plasmonic substrate for SPRS, SERS, and SEF. The optical response of AgFoN fabricated with colloids of different sizes is highly sensitive to the adsorption of MUA molecules, with SERS and SEF spectra obtained from the same molecules. FDTD simulations are used to explain the size-dependent SERS behaviors observed experimentally.
JOURNAL OF MOLECULAR STRUCTURE
(2022)
Article
Spectroscopy
Andra-Sorina Tatar, Cosmin Farcau, Adriana Vulpoi, Sanda Boca, Simion Astilean
Summary: Nanosensors are a promising nanotool for detecting relevant molecules in diseases such as cancer. Sensing platforms using colloidal gold nanoparticles have gained attention for their rapid and real-time detection capabilities. Liquid biomarker sensing allows for non-invasive clinical or laboratory use.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2022)
Review
Nanoscience & Nanotechnology
Ioana Marica, Fran Nekvapil, Maria Stefan, Cosmin Farcau, Alexandra Falamas
Summary: ZnO-based nanostructures have shown great potential for applications in biomedicine, biotechnology, and optical sensors, especially as SERS substrates and for enhancing the fluorescence of analyte molecules. These techniques rely on the structure and properties of nanomaterials to achieve signal enhancement and charge transfer effects.
BEILSTEIN JOURNAL OF NANOTECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Iuliana M. Handrea-Dragan, Adriana Vulpoi, Cosmin Farcau, Ioan Botiz
Summary: This work reports the fabrication of spheres-in-grating assemblies using embossing and convective self-assembly methods. The assembled structures consist of regularly spaced rectangular grooves filled with fluorescent spheres. The fabricated assemblies showed improved performance in terms of photoluminescence spectra and wetting properties compared to other methods.
Article
Chemistry, Multidisciplinary
I. A. Brezestean, N. Tosa, A. Falamas, D. Cuibus, C. M. Muntean, A. Bende, B. Cozar, C. Berghian-Grosan, C. Farcau
Summary: This study reports on the use of self-assembled colloidal nanoparticle films for Surface Enhanced Raman Spectroscopy (SERS) analysis of pesticides. The results demonstrate the high sensitivity and selectivity of this technique, making it suitable for applications in the food industry and environmental monitoring.
FRONTIERS IN CHEMISTRY
(2022)
Article
Polymer Science
Raluca Tarcan, Madalina Handrea-Dragan, Cosmin-Ioan Leordean, Raul Catalin Cioban, Gellert-Zsolt Kiss, Diana Zaharie-Butucel, Cosmin Farcau, Adriana Vulpoi, Simion Simon, Ioan Botiz
Summary: In this study, PMMA/RGO composite thin films were prepared by drop casting mixtures of PMMA solutions and RGO suspensions. The results showed that the thermal conductivity of the composite increased with the concentration of RGO, which is promising for the development of new thermal interface materials.
JOURNAL OF APPLIED POLYMER SCIENCE
(2022)
Article
Chemistry, Applied
Rebeca Moldovan, Karolina Milenko, Elizaveta Vereshchagina, Bogdan-Cezar Iacob, Kenneth Schneider, Cosmin Farcau, Ede Bodoki
Summary: In this study, the electrochemical-surface enhanced Raman spectroscopy (EC-SERS) detection of Thiabendazole (TBZ) in spiked apple juice was reported for the first time. The research utilized electrochemically roughened gold-based screen-printed electrodes (AuSPEs) and portable instrumentation, and by polarizing the substrate (-0.8 V vs Ag/AgCl), the SERS signal of TBZ was enhanced. The LOD in juice was found to be 0.061 ppm, with a wide linear range (0.5-10 mu M) and good intermediate precision (%RSD < 10).
Article
Chemistry, Physical
Ioana Marica, Maria Stefan, Sanda Boca, Alexandra Falamas, Cosmin Farcau
Summary: Evaporation-induced self-assembly is used to organise nanoparticles into various patterns. This study presents a simple drop-coating method for obtaining highly uniform ZnO and TiO2 nanoparticle films without surfactants. The method allows control over the diameter and thickness of the films and can be applied to different substrates.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2023)
Article
Chemistry, Physical
A. Falamas, I. Marica, F. Nekvapil, M. Stefan, G. S. Macavei, L. Barbu-Tudoran, C. Farcau
Summary: In this paper, we developed ZnO nanostructures based platforms for surface enhanced fluorescence emission. ZnO nanoparticles were prepared using a simple chemical precipitation method and decorated with Au nanoparticles. Rhodamine 6G-containing films were designed by incorporating nanostructures in a PVA matrix, which hindered the aggregation of the nanostructures and improved film formation capability. Surface enhanced fluorescence emission of Rhodamine 6G was achieved in the presence of ZnO nanoparticles embedded in the PVA matrix, dependent on the concentration of the fluorophore and ZnO nanoparticles. Au decorated ZnO nanocomposites exhibited no fluorescence enhancement and both types of nanostructures quenched the dye outside of the PVA environment. Time-resolved fluorescence investigations showed that neither ZnO NPs nor Au decorated ZnO nanocomposites modified the dye's lifetime in the presence of PVA, while an additional decay pathway emerged in the absence of the PVA matrix, leading to modified fluorescence lifetime.
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
(2023)
Article
Chemistry, Analytical
Cristina M. Muntean, Denisa Cuibus, Sanda Boca, Alexandra Falamas, Nicoleta Tosa, Ioana Andreea Brezestean, Attila Bende, Lucian Barbu-Tudoran, Rebeca Moldovan, Ede Bodoki, Cosmin Farcau
Summary: The pollution of surface and groundwater bodies by pharmaceuticals is a growing environmental concern that requires routine monitoring. Conventional analytical techniques for quantifying traces of pharmaceuticals are expensive and time-consuming, making field analyses difficult. In this study, we developed an innovative and accessible analytical platform based on self-assembled metal colloidal nanoparticle films for the rapid and sensitive detection of propranolol using Surface Enhanced Raman Spectroscopy (SERS).
Article
Chemistry, Analytical
Andra-Sorina Tatar, Sanda Boca, Alexandra Falamas, Denisa Cuibus, Cosmin Farcau
Summary: In this study, high-density gold nanostar films were fabricated through self-assembly on polystyrene plates, and their use as solid plasmonic substrates for surface-enhanced optical spectroscopies was explored. The films demonstrated dual-mode surface-enhanced fluorescence and surface-enhanced Raman scattering effects under visible and NIR laser excitation. The experimental results were supported by theoretical modelling, and the potential application of these substrates in the detection of biologically relevant molecules was demonstrated.
Article
Nanoscience & Nanotechnology
Alexandra Falamas, Denisa Cuibus, Nicoleta Tosa, Ioana Brezestean, Cristina M. Muntean, Karolina Milenko, Elizaveta Vereshchagina, Rebeca Moldovan, Ede Bodoki, Cosmin Farcau
Summary: This study presents a method for tuning the efficiency of gold films over nanospheres (AuFoN) as surface-enhanced Raman scattering (SERS) substrates in aqueous environment. The optical reflectance and Finite-Difference Time-Domain simulations reveal the dependence of the surface plasmon band on nanospheres' diameter and environment. The correlations between the SERS efficiency and optical response in both air and water provide insights for predicting and optimizing the SERS response of AuFoN in water.
Article
Physics, Multidisciplinary
Cosmin Farcau
Summary: In this work, the optical properties of a linear array colloidal plasmonic-photonic crystal consisting of silver films deposited over linear arrays (grating-like parallel chains) of polystyrene microspheres are investigated. It is found that there exist both propagative plasmonic-photonic hybrid mode and localized surface plasmon mode in these structures. The optical response can be tuned by adjusting the geometrical parameters and the linear plasmonic-photonic crystal exhibits a polarization-selective surface-enhanced Raman scattering effect.
EUROPEAN PHYSICAL JOURNAL PLUS
(2023)
