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Congratulations for our new paper in sensors and actuators A

Magneto-plasmonic response of nickel nano-rings prepared by
electroless method

Akram Poursharif, Peyman Sahebsar, Seyyed Mahmood Monirvaghefi, Seyedeh Mehri Hamidi, Mahshid Kharaziha, Masih Bagheri

Over recent years, there has been increasing interest in the development of magneto-plasmonic nanostructures for advanced sensing applications, many of which have been produced using various lithography and sputtering deposition techniques. This research examines the magneto-plasmonic properties of nickel nano-rings with diameters between 200 and 600 nm, aimed at applications in sensing technologies. Nickel-silver-boron (Ni-Ag-B) nanoarrays were fabricated on ITO substrates through a combination of nano-sphere lithography and selective electroless deposition in a Ni-B and silver nanoparticle bath. Compared to conventional methods, this fabrication process is simpler, more cost-efficient, and produces durable coatings due to the formation of strong covalent bonds. Additionally, the electroless method generally leads to the formation of uniform coatings on complex surfaces. The distinct shape of the nano-rings enhances plasmonic effects by generating a highly concentrated electromagnetic field, outperforming other nanostructures. Unlike thin films, light reflectivity tests showed that the nano-rings exhibited surface plasmon resonance (SPR) in the 470-614 nm range at a 45° incident angle. In the next step, ellipsometry parameters were calculated. To further investigate the nano-rings’ effect, focus on the effective ellipsometry parameters. Additionally, Magneto-Optical Kerr Effect (MOKE) measurements revealed narrow Full Width at Half Maximum (FWHM) peaks at 512 nm and 560 nm, demonstrating their strong potential for highly sensitive detection compared to conventional SPR and ellipsometry-SPR. Finite element simulations using COMSOL further explored how magnetic fields influence the electromagnetic response of the nickel nano-rings, revealing promising applications in optical communication and sensing technologies.

Congratulation for our new paper in JTAP

Temperature effects on the conversion coupling efficiency in dye based Plasmonic Random Laser gain media

Mariam Kadhim Jawad, J. M. Jassim, S. F. Haddawi, S. M. Hamidi

The impact of temperature on the conversion coupling efficiency between Rhodamine 6G (Rh6G) dye and hybrid nanoparticles, composed of gold (Au) and copper (Cu), and its influence on the performance of random lasers is investigated. The study focused on the interaction between the photophysical properties of Rh6G dye molecules and the plasmonic and thermal effects of Au/Cu nanoparticles (NPs) at varying temperatures. We analyzed the interaction between the dye molecules and nanoparticles as a function of pumping energy and temperature focusing on laser parameters laser threshold, full width at half maximum (FWHM), and peak intensity. Our results show that increasing pumping energy and temperature significantly affects the FWHM’s narrowing, and peak intensity enhancement. We found that with increasing pumping energy, the FWHM narrowed to about 8 nm for Au and Cu nanoparticles, and the peak intensity was enhanced to about 40,000 a.u. for AuNPs and 28,000 a.u. for CuNPs. While, we found that with increasing temperature, the FWHM decreased to about 0.6 nm for AuNPs and 0.8 nm for CuNPs, and the peak intensity increased to about 5400 a.u. for AuNPs and 9400 a.u. for CuNPs. This study provides insight into optimizing random laser performance through temperature control, potentially advancing the development of tunable photonic devices.

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Chitosan-C₃N₄-Plasmonic Nanocomposite as a Generation of Scatterer Points for Random Laser Application

S.F. Haddawi^, Amir Reza Sadrolhosseini, R.A. Ejbarah, S. M. Hamidi,  Mahmood Kazemzad

The random laser is a unique optical device based on multi-light scattering, and the scatterer point was used to provide the reflection mechanism. Therefore, selecting the scatterer points is significant in designing the random laser. In this study, plasmonic (gold nanoparticles and silver nanoparticles) chitosan -C₃N₄ nanocomposites were prepared using a laser ablation technique. The prepared samples have been characterized using analytical methods. So, the chitosan-C₃N₄– gold nanoparticles and chitosan-C₃N₄-silver nanoparticles have formed with a particle size of about 24 nm. The experiment confirmed the chitosan-C₃N₄– gold nanoparticles are suitable for random laser and the threshold is higher than other chitosan-C₃N₄– silver nanoparticles and chitosan-C₃N₄ nanocomposites.

Plasmonic nanostructures for color vision deficiency (CVD) management

Color blindness, also known as color vision deficiency (CVD), is a prevalent ocular disorder that hinders distinguishing different colors, a challenge experienced by a considerable portion of the global population (8−10% of males and 0.4−0.5% of females). CVD patients are frequently restricted from crucial professions such as military or police, and cannot recognize colors in public places or media like watching TV. Despite ongoing efforts, there is no definitive cure for color blindness; however, various color filter-based devices such as tinted glasses and contact lenses have been introduced to assist CVD people. Recently, plasmonic nanostructures have attracted significant attention for CVD management by replacing chemical dyes due to their outstanding properties and the adjustability of plasmonic resonances. This study reviews the different wearables utilized in CVD management, such as eyeglasses and contact lenses, with a special emphasis on the innovative plasmonic eye wearables that have emerged in recent advances. The capability to modify the plasmonic properties by manipulating their morphology provides novel perspectives for CVD management and smart ophthalmic wearables.

Congratulations for our new paper

Congratulations for our new paper in The European Physical Journal Plus:

Plasmonic nanostructures for color vision deficiency (CVD) management

N. Roostaei, S. M. Hamidi

Color blindness, also known as color vision deficiency (CVD), is a prevalent ocular disorder that hinders distinguishing different colors, a challenge experienced by a considerable portion of the global population (8−10% of males and 0.4−0.5% of females). CVD patients are frequently restricted from crucial professions such as military or police, and cannot recognize colors in public places or media like watching TV. Despite ongoing efforts, there is no definitive cure for color blindness; however, various color filter-based devices such as tinted glasses and contact lenses have been introduced to assist CVD people. Recently, plasmonic nanostructures have attracted significant attention for CVD management by replacing chemical dyes due to their outstanding properties and the adjustability of plasmonic resonances. This study reviews the different wearables utilized in CVD management, such as eyeglasses and contact lenses, with a special emphasis on the innovative plasmonic eye wearables that have emerged in recent advances. The capability to modify the plasmonic properties by manipulating their morphology provides novel perspectives for CVD management and smart ophthalmic wearables.

Simple method can recover and recycle quantum dots in microscopic lasers

Researchers have discovered a way to recycle the tiny particles used to create supraparticle lasers, a technology that precisely controls light at a very small scale. The breakthrough could help manage these valuable materials in a more sustainable way.

Supraparticle lasers work by trapping light inside a tiny sphere made of special particles called quantum dots, which can absorb, emit, and amplify light very efficiently.They are made by mixing quantum dots in a solution that helps them stick together in tiny bubbles. However, not all attempts succeed, and even successful lasers degrade over time. This leads to wasted materials, which can be expensive.

Recycling method

The idea to recycle these particles came up during a team discussion about the high cost of wasted quantum dots. Dillon Downie, a Ph.D. student in the Institute of Photonics at the University of Strathclyde, suggested a potential solution, and with the support of team leader Dr. Nicolas Laurand, they tested the idea. To their surprise, they were able to recover and reuse the particles to make new lasers.

Dillon said, “Supraparticle lasers are already beginning to be used for targeted drug delivery and sensing applications, as well as for components in compact electronic systems. Nanoparticle aggregates and supraparticle lasers are expected to play an increasingly prominent role in everything from wearable medical devices to ultrabright LEDs.

“Our recycling method reduces costs and environmental impact by minimizing the need for new nanoparticles and the disposal of old ones, and it should be applicable to any colloidal nanoparticle species, especially rare-earth ones.”

In a paper titled “Recycling self-assembled colloidal quantum dot supraparticle lasers,” published in the journal Optical Materials Express, the Strathclyde researchers describe how they recycled quantum dots from used lasers to make new ones that work just as well as the originals.

Dillon said, “We envision this method being used to extend the life cycle of supraparticles, which could be repurposed for various applications such as medical biosensors, representing a significant advance toward sustainable nanoengineering.”

Simple method

The recycling process starts by breaking apart the used lasers by heating the particles and exposing them to sound waves. The quantum dots were then separated from impurities using a mix of oil and water, followed by filtering and coating the particles to restore their properties. Finally, the research team tested the recycled dots to ensure they could still emit light effectively and used them to create new lasers.

This method recovered 85% of the original quantum dots, which still performed almost as well as new ones. The recycled dots were then used to make lasers that worked just like the originals.

The team plans to study how recycling affects the performance of the quantum dots over time and to develop ways to recycle more complex or specialized particles.

Dillon added, “Our simple method doesn’t need fancy equipment, so it can be used in most labs. This is a big step toward making advanced materials more sustainable.”

Unveiling of the first Iranian atomic clock by the Magnetoplasmonic laboratory in the fifth photonics and laser exhibition of Iran 2024

Shahid Beheshti University’s magnetoplasmonics laboratory unveiled the first Iranian atomic clock in the fifth photonics and laser exhibition of Iran in 4th November of 2024. This laboratory started its activity a few years ago in the field of construction and design of atomic steam cells and also has the history of building the first Iranian rubidium atomic steam cell in its portfolio. This atomic clock based on rubidium atom vapor cell with microwave stimulation is the first atomic clock made in Iran. Dr.Hamidi, the professor of Shahid Beheshti university , is the supervisor of this project.

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Recent Applications of Quantum Plasmonic Techniques for Detection of Toxic Materials

Amir Reza Sadrolhosseini, Seyedeh Mehri Hamidi

News On Plasmonics

In these days, the Journal of Scientific Reports published a new paper entitled as “Angular surface plasmon resonance‑based sensor with a silver nanocomposite layer for effective water pollution detection”

For sensing various samples of polluted water and various sodium chloride concentrations using an angular surface plasmon resonance (ASPR), we have introduced a conventional structure and a hybrid heterostructure in the current research. The suggested structures are composed of silver metal, dielectric layers, silver nanocomposite, and a sensing medium. The refectance spectra of all structures in the visible region were obtained through the utilization of the transfer matrix method by using the angular interrogation method depending on the Kretschmann confguration. Through our findings, five substrate parameters have been optimized to attain the utmost level of sensitivity across all structures: the thickness of Ag-metal, the type and thickness of dielectric materials, the host material type and the volume fraction of nanoparticles for the nanocomposite layer. In this regard, the suggested sensor provides excellent performance with a sensitivity of 448.1°/RIU, signal-to-noise ratio of 0.787, sensor resolution of 0.284°, and figure of merit of 78.766 RIU−1. Therefore, we believe that the introduced design of our ASPR sensor presents a good candidate for an accurate and effcient detection of low concentrations of contaminated water and sodium chloride as well.

News On Plasmonic Biosensors

In these days, the journal of Sensors published a new paper entitled as “New Biosensor for Determination of Neuropilin-1 with Detection by Surface Plasmon Resonance Imaging“

Abstract: Neuropilin-1 is transmembrane protein with soluble isoforms. It plays a pivotal role in both physiological and pathological processes. NRP-1 is involved in the immune response, formation of neuronal circuits, angiogenesis, survival and migration of cells. The specific SPRI biosensor for the determination of neuropilin-1 was constructed using mouse monoclonal antibody that captures unbound NRP-1 form body fluids. The biosensor exhibits linearity of the analytical signal between 0.01 and 2.5 ng/mL, average precision value 4.7% and recovery between 97% and 104%. The detection limit is 0.011 ng/mL, and the limit of quantification is 0.038 ng/mL. The biosensor was validated by parallel determination of NRP-1 in serum and saliva samples using the ELISA test, with good agreement of the results.