Archive: September 27, 2022

Congratulations for our new paper in Journal of Sensors and Actuators A: Physical

Ketamine Plasmonic Sensor Using Polyaniline-rGO-Fe3O4 Nanocomposite Thin Layer

Amir Reza Sadrolhosseini, Seyedeh Mehri Hamidi*, Mahmood Kazamzad, Ali Rafiei, Farnaz Amouyan, Somayeh Sadeghi

Ketamine is a narcotic and palliative substance and the measurement of the low concentration of ketamine is a great intense interest matter in biotechnology and medicine. The surface plasmon resonance imaging method can monitor the low concentration of bio-substance such as ketamine and dopamine. The reduced graphene oxide-Fe3O4 nanoparticles and polyaniline-reduced graphene oxide-Fe3O4 nanocomposite layers as the sensing layer were prepared using sonication and electro-deposition methods, respectively. The average particle size of Fe3O4 was 38.53 nm, and the sensing layer thickness was in the range of 19 to 24.5 nm. The morphology, functional group, and contribution of chemical elements were investigated using field emission electron microscopy; Fourier transforms infrared spectroscopy, and energy-dispersive X-ray spectroscopy, respectively. The surface plasmon resonance imaging pattern confirmed that the minimum concentration for detecting ketamine, the sensitivity of the sensor, and the response time were about 0.1 mg/L, 0.044, and 220 s, respectively. The affinity constant is 11.19 for the detection of ketamine, and the tendency of the sensing layer to bind the ketamine is higher than dopamine and glucose.

News On Lasers

In this days, the Journal of Light: Science & Applications published a new paper entitled as “Quantum dot lasing from a waterproof and stretchable polymer film”

Colloidal quantum dots (QDs) are excellent optical gain materials that combine high material gain, a strong absorption of pump light, stability under strong light exposure and a suitability for solution-based processing. The integration of QDs in laser cavities that fully exploit the potential of these emerging optical materials remains, however, a challenge. In this work, we report on a vertical cavity surface emitting laser, which consists of a thin film of QDs embedded between two layers of polymerized chiral liquid crystal. Forward directed, circularly polarized defect mode lasing under nanosecond-pulsed excitation is demonstrated within the photonic band gap of the chiral liquid crystal. Stable and long-term narrow-linewidth lasing of an exfoliated free-standing, flexible film under water is obtained at room temperature. Moreover, we show that the lasing wavelength of this flexible cavity shifts under influence of pressure, strain or temperature. As such, the combination of solution processable and stable inorganic QDs with high chiral liquid crystal reflectivity and effective polymer encapsulation leads to a flexible device with long operational lifetime, that can be immersed in different protic solvents to act as a sensor.

Congratulations for our new paper in Journal of Optics Communications

All-dielectric achiral etalon-based metasurface: Ability for glucose sensing

N. Roostaei, S. M. Hamidi

In this study, an all-dielectric achiral etalon-based metasurface proposed and experimentally investigated for the glucose sensing application. For this purpose, all-dielectric metasurfaces based on etalon nanostructure have been fabricated using the soft nano lithography method and also a flow cell channel has been designed and fabricated for glucose sensing using the proposed all-dielectric nanostructure. Finally, glucose sensing based on circular dichroism (CD) spectroscopy was investigated using the sensing chip based on all-dielectric metasurface. In addition, the proposed nanostructure was simulated using the finite-difference time-domain (FDTD) method and a good agreement between the experimental and simulation results has been achieved. Therefore, proposed sensing chip can be useful for sensing applications of the glucose or other biological fluids.

Congratulations for our new paper in Journal of Optik

Tunable plasmon induced transparency in one-dimensional gold nano-grating as a new kind of neuro-transmitter sensor

Hussam Jawad Kadhim, Haider Al-Mumen, H.H. Nahi, S.M. Hamidi*

The plasmon induce-transparency (PIT) is a promising research area for slow light, nonlinearity, metamaterial, and sensing applications. This physical phenomenon originated in plasmonic nanostructures with the interference between wideband (superradiant) and narrowband (subradiant) states (modes). We report tunable plasmon-induced transparency in one-dimensional gold nano-grating electro-plasmonic consisting of a straight nanorod of gold grating embedded in the polycarbonate layer, which combines the plasmonic properties of gold nanostructure and the external applying voltage. Tunable PIT is achieved under the excitation of power supply from 1 v to 3 v, with spectroscopy employed to monitor the changes of transmission spectrum with different voltages applied on the plasmonic periodically with the surface plasmon resonance. Also, we use this plasmonic sensor to sense and monitor dopamine concentration as a neurotransmitter. The results revealed that we obtain a clear sharp window for tunable PIT and a good sensor to sense the dopamine concentration.

News on Active Plasmonics

The journal of Chemical Reviews published a paper entitled as “Active Plasmonics: Principles, Structures, and Applications”

Active plasmonics is a burgeoning and challenging subfield of plasmonics. It exploits the active control of surface plasmon resonance. In this review, a first-ever in-depth description of the theoretical relationship between surface plasmon resonance and its affecting factors, which forms the basis for active plasmon control, will be presented. Three categories of active plasmonic structures, consisting of plasmonic structures in tunable dielectric surroundings, plasmonic structures with tunable gap distances, and self-tunable plasmonic structures, will be proposed in terms of the modulation mechanism. The recent advances and current challenges for these three categories of active plasmonic structures will be discussed in detail. The flourishing development of active plasmonic structures opens access to new application fields. A significant part of this review will be devoted to the applications of active plasmonic structures in plasmonic sensing, tunable surface-enhanced Raman scattering, active plasmonic components, and electrochromic smart windows. This review will be concluded with a section on the future challenges and prospects for active plasmonics.