arXiv subjects

Igor Nabiev

Publications and source records attributed to Igor Nabiev.

4 recordsLinked to original sources

arXiv2026

Optically Encoded Suspension Microarrays: Materials, Design Strategies, and Future Directions for Multiplexed Bioanalysis

Suspension microarrays based on optically encoded microbeads have become one of the most versatile platforms for multiplexed bioanalysis because they combine solution-phase reaction kinetics, flexible assay design, and high-throughput detection. However, despite more than two decades of intense research, no consensus has emerged regarding the optimal strategies for particle encoding, surface functionalization, and signal decoding. Progress has mainly been driven by incremental improvements in individual materials rather than by systematic comparison of competing technological concepts. This review critically evaluates the main approaches to the fabrication of optically encoded microbeads, including post-synthetic (swelling and layer-by-layer assembly) and in situ encoding strategies, and proposes a mechanistic classification of in situ methods of particle formation into polymerization-driven and confinement-controlled ones. Instead of comparing the fabrication methods solely in terms of encoding capacity, we assess their relative merits in terms of structural control, code stability, scalability, compatibility with biofunctionalization, and suitability for clinical implementation. We further examine the strengths and limitations of organic fluorophores, aggregation-induced emission luminogens, semiconductor quantum dots, and upconversion nanoparticles and show that no encoding material is universally optimal and that performance is determined by trade-offs between optical properties, manufacturing complexity, and stability in biological media. We argue that future progress will depend not as much on increasing the theoretical number of optical codes as on improving the code reproducibility, minimizing spectral crosstalk and nonspecific interactions, and employing microfluidic fabrication, antifouling surface chemistry, automated spectral decoding, and artificial intelligence-assisted data analysis. These developments are expected to transform suspension microarrays from multiplexed analytical tools into standardized lab-on-a-microbead platforms suitable for next-generation clinical diagnostics.

physics.med-ph↗

arXiv2023

On-demand reversible switching of the emission mode of individual semiconductor quantum emitters using plasmonic metasurfaces

The field of quantum technology has been rapidly expanding in the past decades, yielding numerous applications as quantum information, quantum communication and quantum cybersecurity. The central building block for these applications is a quantum emitter (QE), a controllable source of single photons or photon pairs. Semiconductor QEs such as perovskite nanocrystals (PNCs) and semiconductor quantum dots (QDs) have been demonstrated to be a promising material for pure single-photon emission, and their hybrids with plasmonic nanocavities may serve as sources of photon pairs. Here we have designed a system in which individual quantum emitters and their ensembles can be traced before, during, and after the interaction with the external plasmonic metasurface in controllable way. Upon coupling the external plasmonic metasurface to the array of QEs, the individual QEs switch from single-photon to photon-pair emission mode. Remarkably, this method does not affect the chemical structure and composition of the QEs, allowing them to return to their initial state after decoupling from the plasmonic metasurface. By employing this approach, we have successfully demonstrated the reversible switching of the ensemble of individual semiconductor QEs between single-photon and photon pair emission modes. This significantly broadens the potential applications of semiconductor QEs in quantum technologies.

physics.optics↗

arXiv2021

Strong exciton-photon coupling with colloidal quantum dots in a tuneable microcavity

Polariton emission from optical cavities integrated with various luminophores has been extensively studied recently due to the wide variety of possible applications in photonics, particularly promising in terms of fabrication of low-threshold sources of coherent emission. Tuneable microcavities allow extensive investigation of the photophysical properties of matter placed inside the cavity by deterministically changing the coupling strength and controllable switching from weak to strong and ultra-strong coupling regimes. Here we demonstrate room temperature strong coupling of exciton transitions in CdSe/ZnS/CdS/ZnS colloidal quantum dots with the optical modes of a tuneable low-mode-volume microcavity. Strong coupling is evidenced by a large Rabi splitting of the photoluminescence spectra depending on the detuning of the microcavity. A coupling strength of 154 meV has been achieved. High quantum yields, excellent photostability, and scalability of fabrication of QDs paves the way to practical applications of coupled systems based on colloidal QDs in photonics, optoelectronics, and sensing.

cond-mat.mes-hall↗

arXiv2020

Polariton-assisted donor-acceptor role reversal in resonant energy transfer between organic dyes strongly coupled to electromagnetic modes of a tuneable microcavity

Resonant interaction between excitonic transitions of molecules and localized electromagnetic field allows the formation of hybrid light-matter polaritonic states. This hybridization of the light and the matter states has been shown to be able to significantly alter the intrinsic properties of molecular ensembles placed inside the optical cavity. Here, we have achieved strong coupling between the excitonic transition in typical oligonucleotide-based molecular beacons labelled with a pair of organic dye molecules, demonstrating an efficient donor to acceptor resonance energy transfer, and the tuneable open-access cavity mode. The photoluminescence of this hybrid system under non-resonant laser excitation and the dependence of the relative population of light-matter hybrid states on cavity detuning have been characterized. Furthermore, by analysing the dependence of the relaxation pathways between energy states in this system, we have demonstrated that predominant strong coupling of the cavity photon to the exciton transition in the donor dye molecule can lead to such a large an energy shift that the energy transfer from the acceptor exciton reservoir to the mainly donor lower polaritonic state can be achieved, thus yielding the chromophores donor-acceptor role reversal or carnival effect. Our experimental data confirm the theoretically predicted possibility for confined electromagnetic fields to control and mediate polariton-assisted remote energy transfer thus paving the way to new approaches to remote-controlled chemistry, energy harvesting, energy transfer and sensing.

cond-mat.mes-hall↗