Person: Melle Hernández, Sonia
Universidad Complutense de Madrid
Faculty / Institute
Óptica y Optometría
Now showing 1 - 10 of 36
PublicationDynamic population gratings in highly doped erbium fibers(OSA Publising, 2011-06-07) Melle Hernández, Sonia; Gómez Calderón, Óscar; Zhuo, Zhong C.; Antón Revilla, Miguel Ángel; Carreño Sánchez, FernandoThe efficiency of the dynamic population gratings recorded in highly doped erbium fibers has been studied. We find that the grating response increases with optical density, although the presence of erbium ion pairs in fibers with ion density of the order of 6:3 × 1025 m−3 degrades the grating efficiency. The experimental results have been reproduced including inhomogeneous upconversion processes in the nonlinear coupled-wave equations. PublicationOligonucleotide Sensor Based on Selective Capture of Upconversion Nanoparticles Triggered by Target Induced DNA Inter-Strand Ligand Reaction(Amer Chemical Soc., 2017-03-23) Méndez González, Diego; Laurenti, Marco; Latorre, Alfonso; Somoza, Álvaro; Vázquez, Ana; Negredo, Ana Isabel; López Cabarcos, Enrique; Calderón, Oscar Gómez; Melle Hernández, Sonia; Rubio Retama, JorgeWe present a sensor that exploits the phenomenon of upconversion luminescence to detect the presence of specific sequences of small oligonucleotides like miRNAs among others. The sensor is based on NaYF4:Yb,Er@SiO2 nanoparticles functionalized with ssDNA that contain azide groups on the 3' ends. In the presence of a target sequence, inter-strand ligation is possible via click-reaction between one azide of the upconversion probe and a DBCO-ssDNA-biotin probe present in the solution. As result of this specific and selective process, biotin is covalently attached to the surface of the upconversion nanoparticles. The presence of biotin on the surface of the nanoparticles allows their selective capture on a streptavidin-coated support, giving a luminescent signal proportional to the amount of target present in the test samples. With the aim of studying the analytical properties of the sensor, total RNA samples were extracted from healthy mosquitoes and spiked-in with a specific target sequence at different concentrations. The result of these experiments revealed that the sensor was able to detect 10-17 moles (100 fM) of the target sequence in mixtures containing 100 ng of total RNA per well. Similar limit of detection was found for spiked human serum samples, demonstrating its suitability for detecting specific sequences of small oligonucleotides under real conditions. By contrast, under the presence of non-complementary sequences or sequences having mismatches, the luminescent signal was negligible or conspicuously reduced. PublicationIn Vivo Near-Infrared Imaging Using Ternary Selenide Semiconductor Nanoparticles with an Uncommon Crystal Structure(Wiley, 2021-09-23) Yao, Jingke; Lifante, José; Rodríguez Sevilla, Paloma; Fuente Fernández, Rosa María de la; Sanz Rodríguez, Francisco; Ortgies, Dirk H.; Gómez Calderón, Óscar; Melle Hernández, Sonia; Ximendes, Erving; Jaque García, Daniel; Marin, RiccardoThe implementation of in vivo fluorescence imaging as a reliable diagnostic imaging modality at the clinical level is still far from reality. Plenty of work remains ahead to provide medical practitioners with solid proof of the potential advantages of this imaging technique. To do so, one of the key objectives is to better the optical performance of dedicated contrast agents, thus improving the resolution and penetration depth achievable. This direction is followed here and the use of a novel AgInSe2 nanoparticle-based contrast agent (nanocapsule) is reported for fluorescence imaging. The use of an Ag2Se seeds-mediated synthesis method allows stabilizing an uncommon orthorhombic crystal structure, which endows the material with emission in the second biological window (1000–1400 nm), where deeper penetration in tissues is achieved. The nanocapsules, obtained via phospholipid-assisted encapsulation of the AgInSe2 nanoparticles, comply with the mandatory requisites for an imaging contrast agent—colloidal stability and negligible toxicity—and show superior brightness compared with widely used Ag2S nanoparticles. Imaging experiments point to the great potential of the novel AgInSe2-based nanocapsules for high-resolution, whole-body in vivo imaging. Their extended permanence time within blood vessels make them especially suitable for prolonged imaging of the cardiovascular system. PublicationLíneas de investigación del Grupo UCM de Física del Láser, Óptica Cuántica y Óptica No Lineal(Sociedad Española de óptica, 2011) Antón Revilla, Miguel Ángel; Arrieta Yáñez, Francisco; Cabrera Granado, Eduardo; Carreño Sánchez, Fernando; Ezquerro Rodríguez, José Miguel; Gómez Calderón, Óscar; Gonzalo Fonrodona, Isabel; Guerra Pérez, José Manuel; Melle Hernández, Sonia; Soler Rus, Miguel Odín; Sánchez Balmaseda, Margarita María; Weigand Talavera, Rosa MaríaEn este trabajo presentamos las líneas de investigación del Grupo de Física del Láser, Óptica Cuántica y Óptica No Lineal de la UCM. La investigación comprende trabajos experimentales y teóricos en el desarrollo de prototipos de láser, análisis de inestabilidades espacio-temporales en láseres de gran apertura, el estudio de propagación de radiación en régimen de luz lenta y de pulsos ultracortos en medios resonantes y no resonantes, la generación de radiación por procesos no lineales y el estudio de memorias ópticas por eco fotónico. PublicationControl of upconversion luminescence by gold nanoparticle size: from quenching to enhancement(RSC, 2019-08-07) Méndez González, Diego; Melle Hernández, Sonia; Gómez Calderón, Óscar; Laurenti, Marco; Cabrera Granado, Eduardo; Egatz-Gómez, Ana; López Cabarcos, Enrique; Rubio Retama, Jorge; Díaz García, ElenaMetallic nanostructures have the potential to modify the anti-Stokes emission of upconverting nanoparticles (UCNPs) by coupling their plasmon resonance with either the excitation or the emission wavelength of the UCNPs. In this regard gold nanoparticles (AuNPs) have often been used in sensors for UCNP luminescence quenching or enhancement, although systematic studies are still needed in order to design optimal UCNP–AuNP based biosensors. Amidst mixed experimental evidence of quenching or enhancement, two key factors arise: the nanoparticle distance and nanoparticle size. In this work, we synthesize AuNPs of different sizes to assess their influence on the luminescence of UCNPs. We find that strong luminescence quenching due to resonance energy transfer is preferentially achieved for small AuNPs, peaking at an optimal size. A further increase in the AuNP size is accompanied by a reduction of luminescence quenching due to an incipient plasmonic enhancement effect. This enhancement counterbalances the luminescence quenching effect at the biggest tested AuNP size. The experimental findings are theoretically validated by studying the decay rate of the UCNP emitters near a gold nanoparticle using both a classical phenomenological model and the finite-difference time-domain method. Results from this study establish general guidelines to consider when designing sensors based on UCNPs–AuNPs as donor–quencher pairs, and suggest the potential of plasmon-induced luminescence enhancement as a sensing strategy. PublicationUltrafast photochemistry produces superbright short-wave infrared dots for low-dose in vivo imaging(Nature Publishing Group, 2020-06-10) Santos, Harrison D. A.; Zabala Gutiérrez, Irene; Shen, Yingli; Lifante, José; Ximendes, Erving; Laurenti, Marco; Méndez González, Diego; Melle Hernández, Sonia; Gómez Calderón, Óscar; López Cabarcos, Enrique; Fernández Monsalve, Nuria; Chavez Coria, Irene; Lucena Agell, Daniel; Monge, Luis; Mackenzie, Mark D.; Marqués Hueso, José; Jones, Callum M. S.; Jacinto, Carlos; Rosal, Blanca, del; Kar, Ajoy K.; Rubio Retama, Jorge; Jaque García, DanielOptical probes operating in the second near-infrared window (NIR-II, 1,000-1,700 nm), where tissues are highly transparent, have expanded the applicability of fluorescence in the biomedical field. NIR-II fluorescence enables deep-tissue imaging with micrometric resolution in animal models, but is limited by the low brightness of NIR-II probes, which prevents imaging at low excitation intensities and fluorophore concentrations. Here, we present a new generation of probes (Ag2S superdots) derived from chemically synthesized Ag2S dots, on which a protective shell is grown by femtosecond laser irradiation. This shell reduces the structural defects, causing an 80-fold enhancement of the quantum yield. PEGylated Ag2S superdots enable deep-tissue in vivo imaging at low excitation intensities (<10 mW cm−2) and doses (<0.5 mg kg−1), emerging as unrivaled contrast agents for NIR-II preclinical bioimaging. These results establish an approach for developing superbright NIR-II contrast agents based on the synergy between chemical synthesis and ultrafast laser processing. PublicationBoosting the Near-Infrared Emission of Ag2S Nanoparticles by a Controllable Surface Treatment for Bioimaging Applications(ACS Publications, 2022-01) Zabala Gutiérrez, Irene; Gerke, Christoph; Shen, Yingli; Ximendes, Erving Clayton; Manso Silvan, Miguel; Marin, Riccardo; Jaque García, Daniel; Gómez Calderón, Óscar; Melle Hernández, Sonia; Rubio Retama, JorgeAg2S nanoparticles are the staple for high-resolution preclinical imaging and sensing owing to their photochemical stability, low toxicity, and photoluminescence (PL) in the second near-infrared biological window. Unfortunately, Ag2S nanoparticles exhibit a low PL efficiency attributed to their defective surface chemistry, which curbs their translation into the clinics. To address this shortcoming, we present a simple methodology that allows to improve the PL quantum yield from 2 to 10%, which is accompanied by a PL lifetime lengthening from 0.7 to 3.8 μs. Elemental mapping and X-ray photoelectron spectroscopy indicate that the PL enhancement is related to the partial removal of sulfur atoms from the nanoparticle’s surface, reducing surface traps responsible for nonradiative de-excitation processes. This interpretation is further backed by theoretical modeling. The acquired knowledge about the nanoparticles’ surface chemistry is used to optimize the procedure to transfer the nanoparticles into aqueous media, obtaining water-dispersible Ag2S nanoparticles that maintain excellent PL properties. Finally, we compare the performance of these nanoparticles with other near-infrared luminescent probes in a set of in vitro and in vivo experiments, which demonstrates not only their cytocompatibility but also their superb optical properties when they are used in vivo, affording higher resolution images. PublicationPlasmonic effects in excitonic population transfer in a driven semiconductor–metal nanoparticle hybrid system(American Physical Society, 2012) Antón Revilla, Miguel Ángel; Carreño Sánchez, Fernando; Melle Hernández, Sonia; Calderón, Oscar Gómez; Cabrera Granado, Eduardo; Cox, Joel; Singh, Mahi R.We have investigated the coherent transfer of excitonic populations in a semiconductor quantum dot (SQD) modulated by the surface plasmon of a metallic nanoparticle (MNP). The SQD is considered as a three-level V-type atomic system. We applied a transform-limited laser pulse field resonant with the upper atomic levels of the SQD. When the SQD is close enough to the MNP, the otherwise equally populated atomic levels can be selectively excited. Selectivity population can be achieved by two physical mechanisms: an enhancement of the Rabi frequencies that drive the optical transitions, which depends on the polarization arrangement, and a frequency shift of the optical transitions that leads to a dynamical detuning. PublicationSlow and fast light based on coherent population oscillations in erbium-doped fibres(IOP Publishing, Ltd., 2010-09-24) Arrieta Yáñez, Francisco; Gómez Calderón, Óscar; Melle Hernández, SoniaIn this paper we review the main results on slow and fast light induced by coherent population oscillations in optical fibres doped with erbium ions. We explain the physics behind this technique and we describe the experimental realization. Finally, we summarize some recent advances in this field and future goals. PublicationSpectral hole burning in erbium-doped fibers for slow light(OSA Publishing, 2012) Melle Hernández, Sonia; Gómez Calderón, Óscar; Antón Revilla, Miguel Ángel; Carreño Sánchez, Fernando; Egatz-Gómez, AnaThe homogeneous linewidth of the transition I15/24−I13/24 in highly doped erbium fibers and its dependence with temperature in the range from 10 to 50 K are experimentally characterized using spectral hole burning. The homogeneous linewidth dependence with temperature is quadratic above 20 K where homogeneous broadening is dominated by two-phonon Raman processes, and linear at lower temperatures where direct phonon processes occur. This characteristic power-law dependence was also derived from transmittance measurements. The solution of nonlinear field equations using the results obtained from our experiments predicts that Gaussian probe pulses propagate at subluminal speed through the narrow spectral holes burned in erbium-doped fibers. For gigahertz pulses in the telecommunication window, a fractional delay as high as 0.6 is predicted.