Archives July 2021

News On Quantum Plasmonics

In this days, the journal of Advanced Materials publishes a new paper entitled as “Quantum Plasmonics: Energy Transport Through Plasmonic Gap”

At the interfaces of metal and dielectric materials, strong light–matter interactions excite surface plasmons; this allows electromagnetic field confinement and enhancement on the sub-wavelength scale. Such phenomena have attracted considerable interest in the field of exotic material-based nanophotonic research, with potential applications including nonlinear spectroscopies, information processing, single-molecule sensing, organic-molecule devices, and plasmon chemistry. These innovative plasmonics-based technologies can meet the ever-increasing demands for speed and capacity in nanoscale devices, offering ultrasensitive detection capabilities and low-power operations. Size scaling from the nanometer to sub-nanometer ranges is consistently researched; as a result, the quantum behavior of localized surface plasmons, as well as those of matter, nonlocality, and quantum electron tunneling is investigated using an innovative nanofabrication and chemical functionalization approach, thereby opening a new era of quantum plasmonics. This new field enables the ultimate miniaturization of photonic components and provides extreme limits on light–matter interactions, permitting energy transport across the extremely small plasmonic gap. In this review, a comprehensive overview of the recent developments of quantum plasmonic resonators with particular focus on novel materials is presented. By exploring the novel gap materials in quantum regime, the potential quantum technology applications are also searched for and mapped out.

Congratulation for our new paper in Scientific Reports

Detection of Scorpion Venom by Optical Circular Dichroism Method

Y. Mazhdi, S. M. Hamidi

Various efforts have been made to detect minimum amounts of any toxic materials in water or the neurotoxic effect of venom (Odontobuthus Doriae Scorpion) in the humans҆ blood serum nerve by high-sensitivity, accurate, and low-cost sensors in order to enhance life style. Therefore, the present study was done to investigate reliability of two-dimensional plasmonic structure and circular dichroism (CD) in toxic samples in order to measure and determine venom concentrations and its neurotoxic effect on humans҆ blood serum Neurotransmitter analytes. Our results confirmed dependency of CD signal to neurotoxic effect of venom concentrations and good sensitivity of this sensor with the help of achiral plasmonic structure.

Congratulations for Our new paper in Journal of Physica Scirpta

Random laser action in the visible region by dye-based sliver Nano-hexagonal colloid media

R. A. Ejbarah, J. M. Jassim, H. Yazdanfar, S. M. Hamidi

In our attempt to reduce the threshold for dye-based random lasers, a new kind of random lasing media is demonstrated based on silver nano-hexagonal as scattering centers. For this purpose, we use a chemical method to synthesize nano hexagonal silver scatterer points and dissolve them in polymer and Rhodamine B dye media in different concentrations and different sizes. Our results from these samples under different pumping power, confirm the strong dependence on the sizes and concentration on the transition from incoherent to the coherent random laser, which is starts from 0.061 MW/cm² as threshold power. This threshold power and linewidths of emission peaks decrease by an increase in the size and concentrations of nano-hexagonal points to 0.04 MW/cm² and 0.2 nm, respectively.

News On Plasmonics

Journal of Sensors publishes a paper entitled as “Plasmonics for Telecommunications Applications”

Abstract: Plasmonic materials, when properly illuminated with visible or near-infrared wavelengths, exhibit unique and interesting features that can be exploited for tailoring and tuning the light radiation and propagation properties at nanoscale dimensions. A variety of plasmonic heterostructures have been demonstrated for optical-signal filtering, transmission, detection, transportation, and modulation. In this review, state-of-the-art plasmonic structures used for telecommunications applications are summarized. In doing so, we discuss their distinctive roles on multiple approaches including beam steering, guiding, filtering, modulation, switching, and detection, which are all of prime importance for the development of the sixth generation (6G) cellular networks.

News On Bio-Photonics

The Journal of Sensors and Actuators B: Chemical published a paper entitled as “Surface plasmon resonance biosensor for enzyme-free amplified microRNA detection based on gold nanoparticles and DNA super sandwich”

A novel enzyme-free amplified surface plasmon resonance (SPR) biosensor for microRNA (miRNA) detection was developed based on gold nanoparticles (AuNPs) coupled with DNA supersandwich. In the detection strategy, the DNA-linked AuNPs as the primary amplification element, not only hybridized with the capture DNA on the Au film to amplify SPR signal but also initiated the subsequent secondary amplification, i.e. DNA supersandwich formation of two report probes. In the presence of target, stem–loop structure of capture DNA on the Au film surface was unfolded, and DNA-linked AuNPs were bound to Au film by hybridization with terminus of capture DNA. Then, the carried assistant DNA on the AuNPs could trigger an alternative hybridization reaction of two report probes, resulting in the formation of DNA supersandwich. Due to the electronic coupling between localized plasmon of AuNPs and the surface plasmon wave associated with Au film, as well as the enhancement of the refractive index of the medium next to the metal film caused by DNA supersandwich structure, the shift of resonance angle was enhanced obviously. By employing the enzyme-free dual signal amplification strategies, as low as ca. 8 fM miRNA-21 could be detected. Moreover, this assay also showed high selectivity toward single-base mismatch, and demonstrated its applicability for the target detection in human serum. This work may provide great potential applications in future clinical analysis.