38 research outputs found
On the Photothermal Response of DNA–Au Core/Shell Nanotoroids as Potential Agents for Photothermal Therapies
No full textPublisher Copyright: © 2024 The Author(s). Small Structures published by Wiley-VCH GmbH.Plasmonic nanoparticles play a pivotal role in various research areas due to their exceptional optical and thermo-optical properties, like high spectral tunability and efficient light-to-heat conversion. Gold, with its biocompatibility, low cytotoxicity, and tunable resonances, makes gold nanoparticles ideal for photothermal therapies. Geometries, including spheres, core–shells, rods, disks, stars, nanocages, and nanotoroids, are extensively studied, with the gold nanodoughnut emerging as one of the most promising ones due to its ability to produce high temperatures and rotational stability. Nevertheless, the fabrication of metallic toroidal shapes remains a challenge. Recent advances in DNA-based nanotechnology, especially DNA-origami techniques, provide feasible route for the fabrication of this geometry through metallization reactions or attachment of metal nanoparticles. However, particles manufactured using this method possess a DNA core that influences their thermoplasmonic performance. In this work, a theoretical investigation is conducted on the thermoplasmonic response of DNA-origami-based core/shell toroids (CSTs) for photothermal applications. Key parameters that optimize the CST thermoplasmonic response are identified, and compared with their solid counterparts and discrete metallic coatings. Additionally, the CSTs tolerance to random rotations is assessed, providing insights into their behavior in fluidic environments and implications for its practical consideration.Peer reviewe
Amplified linear and nonlinear chiral sensing assisted by anapole modes in hybrid metasurfaces
No full textThe interaction between chiral molecules and circularly polarized light is largely influenced by the local optical chirality density. This interaction prompts substantial demand of the design of nanophotonic platforms capable of enhancing such effects across large and accessible volumes. Such a magnification requires nanostructures that provide strong electric and magnetic field enhancements while preserving the phase relation of circular light. Dielectric nanostructures, particularly those able to support resonances, are ideal candidates for this task due to their capacity for high electric and magnetic field enhancements. On the other hand, efficient third harmonic generation calls for strong electric field resonances within dielectric materials, a feature often boosted by incorporating plasmonic materials into hybrid systems. In this work, we numerically propose a coupled silicon disk-gold ring system that can exploit the anapole-induced field confinement to provide a broadband magnified circular dichroism under realistic conditions, reaching values up to a 230-fold enhancement. We also demonstrate that this structure can be employed as an efficient third harmonic generator which, when integrated with chiral media, enables an 800-fold enhancement in circular dichroism. Furthermore, we show that pulsed illumination at intensities up to 10 GW/cm2 does not induce temperature increments that could potentially damage the samples. These findings suggest that this system can be a promising and versatile approach towards ultrasensitive chiral sensing.This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Appl. Phys. Lett. 124, 251701 (2024) and may be found at 10.1063/5.0212393. Copyright (2024) Authors. This article is distributed under a Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International (CC BY-NC-ND) Licens
Enhanced optical chirality with directional emission of Surface Plasmon Polaritons for chiral sensing applications
No full text7 pags., 6 figs.Chirality is a crucial aspect in life sciences, where systems capable of enhancing the chiroptical properties of molecules are highly demanded. In this work, we present a numerical proof of concept of a novel approach towards chiral sensing, consisting in the measurement of chiroptical properties via the directional emission of Surface Plasmon Polaritons (SPPs) on a metasurface. Based on the enhanced differential absorption between right and left circularly polarized light upon interaction with a metasurface made of high refractive index dielectric unit cells, a polarization-dependent SPP differential emission is obtained. Furthermore, the plasmonic emission direction is entirely dependent on the polarization handedness. Using FDTD numerical methods we report Circular Dichroism signals of around − 6° for the unit cell, with threefold dissymmetry factor enhancements in places accessible to analytes. We believe that this work sets a brand-new branch in chiral sensing towards faster, real-time measurements.The authors gratefully acknowledge financial support from Spanish national project (No. PGC2018–096649-B-I). V. G. thanks the “ENSEMBLE3 - Centre of Excellence for nanophotonics, advanced materials and novel crystal growth-based technologies” project (GA No. MAB/2020/14) carried out within the International Research Agendas programme of the Foundation for Polish Science co-financed by the European Union under the European Regional Development Fund and the European Union’s Horizon 2020 research and innovation programme Teaming for Excellence (GA. No. 857543) for support of this work. G. S. thanks the Ministry of education for his collaboration grant. J. G-C and P. A thank the Ministry of science and Innovation of Spain for their grants, FPI and Ramon y Cajal Fellowship (No. RYC-2016–20831), respectively
Resistance profile and Molecular Characteristics of the CTX-M-9-Producing <i>E</i>. <i>coli</i> Isolates.
No full textResistance profile and Molecular Characteristics of the CTX-M-9-Producing E. coli Isolates.</p
Epidemiological and Clinical Characteristics of the Patients with CTX-M-9-Producing <i>E</i>. <i>coli</i> Isolates.
No full textEpidemiological and Clinical Characteristics of the Patients with CTX-M-9-Producing E. coli Isolates.</p
PFGE of the CTX-M-9-Producing <i>E</i>. <i>coli</i> Isolates.
No full textC1: Salmonella enterica serovar Braenderup ATCC BAA-664, C2: EC230, C3: EC326, C4: EC419, C5: EC579, C6: EC01, C7: EC284, C8: EC295, C9: EC300, C10: EC600, C11: EC719. The clonally related isolates are underlined: EC579 and EC600 (clone A) and EC419 (clone A2).</p
Thermoplasmonic Polymersome Membranes by In Situ Synthesis
No full textThermoplasmonic nanoparticles, known for releasing heat upon illumination, find diverse applications in catalysis, optics, and biomedicine. Incorporating plasmonic metals within organic vesicle membranes can lead to the formation of nanoreactors capable of regulating temperature-sensitive microscopic processes. Yet, the controlled formation of stable hybrid vesicles displaying significant thermoplasmonic properties remains challenging. This work presents the in situ synthesis of highly efficient thermoplasmonic polymer vesicles, or hybrid polymersomes, by nucleating ∼2 nm gold nanoparticles within preformed polymersome membranes. This process preserves the vesicles’ morphology, stability, and overall functionality. Despite the small size of the embedded plasmonic nanoparticles, these hybrid polymersomes can efficiently convert laser light into a notable temperature increase on a larger scale through collective heating. We develop a theoretical framework that rationalizes the structure–property relations of hybrid polymersomes and accurately predicts their collective thermoplasmonic response. Finally, we demonstrate the biomedical potential of our polymersomes by employing their photothermal properties to induce the hyperthermal death of cancer cells in vitro, an effect amplified by their superior cellular uptake. We envision that these hybrid polymersomes will evolve into a versatile platform for precise control over nanoscale chemical and biological processes through plasmonic heating, unlocking numerous opportunities across various scientific and medical contexts
The circular map of the pEC-PAG-733 genome (Ugene).
No full textThe location of the mcr-1 gene is shown.</p
Alignment of pEC-PAG-733 and pHNSHP45 (accession KP347127.1) produced using MAUVE software.
No full textAlignment of pEC-PAG-733 and pHNSHP45 (accession KP347127.1) produced using MAUVE software.</p
