Person: Melle Hernández, Sonia
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First Name
Sonia
Last Name
Melle Hernández
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Óptica y Optometría
Department
Óptica
Area
Optica
Identifiers
15 results
Search Results
Now showing 1 - 10 of 15
Item Reaching Deeper: Absolute In Vivo Thermal Reading of Liver by Combining Superbright Ag2S Nanothermometers and In Silico Simulations(Advanced Science, 2021) Lifante Cañavate, José; Shen, Yingli; Zabala Gutiérrez, Irene; Rubia Rodríguez, Irene; Ortega, Daniel; Fernández Monsalve, Nuria; Melle Hernández, Sonia; Granado García, Miriam; Rubio Retama, Jorge; Jaque García, Daniel; Ximendes, Erving ClaytonLuminescent nano‐thermometry is a fast‐developing technique with great potential for in vivo sensing, diagnosis, and therapy. Unfortunately, it presents serious limitations. The luminescence generated by nanothermometers, from which thermal readout is obtained, is strongly distorted by the attenuation induced by tissues. Such distortions lead to low signal levels and entangle absolute and reliable thermal monitoring of internal organs. Overcoming both limitations requires the use of high‐brightness luminescent nanothermometers and adopting more complex approaches for temperature estimation. In this work, it is demonstrated how superbright Ag2S nanothermometers can provide in vivo, reliable, and absolute thermal reading of the liver during laser‐induced hyperthermia. For that, a new procedure is designed in which thermal readout is obtained from the combination of in vivo transient thermometry measurements and in silico simulations. The synergy between in vivo and in silico measurements has made it possible to assess relevant numbers such as the efficiency of hyperthermia processes, the total heat energy deposited in the liver, and the relative contribution of Ag2S nanoparticles to liver heating. This work provides a new way for absolute thermal sensing of internal organs with potential application not only to hyperthermia processes but also to advanced diagnosis and therapy.Item Control of upconversion luminescence by gold nanoparticle size: from quenching to enhancement(Nanoscale, 2019) 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.Item In Vivo Near-Infrared Imaging Using Ternary Selenide Semiconductor Nanoparticles with an Uncommon Crystal Structure(Small, 2021) Yao, Jingke; Lifante, José; Rodríguez Sevilla, Paloma; Fuente Fernández, 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.Item FRET distance dependence from upconverting nanoparticles to quantum dots(Journal of physical chemistry C, 2018) Melle Hernández, Sonia; Gómez Calderón, Óscar; Laurenti, Marco; Méndez González, Diego; Egatz-Gómez, Ana; López Cabarcos, Enrique; Cabrera Granado, Eduardo; Díaz García, Elena; Rubio Retama, JorgeFörster resonant energy transfer (FRET) with upconverting nanoparticles (UCNPs) as donors and quantum dots (QDs) as acceptors has been regarded as a promising tool for biosensing applications. In this work, we use time-resolved fluorescence spectroscopy to analyze the UCNP-to-QD FRET and we focus on the most relevant parameter of the FRET phenomenon, UCNP-QD distance. This distance is controlled by a nanometric silica shell around the UCNP surface. We theoretically reproduce the experimental results applying FRET theory to the distribution of emitting erbium ions in the UCNP. This simple model allows us to estimate the contribution of every erbium ion to the final FRET response and to explore different strategies to improve FRET efficiency.Item Upconverting Nanoparticles in Aqueous Media: Not a Dead-End Road. Avoiding Degradation by Using Hydrophobic Polymer Shells(Small, 2021) Méndez González, Diego; Torres Vera, Vivian Andrea; Zabala Gutiérrez, Irene; Gerke, Christoph; Cascales Sedano, Concepción; Rubio Retama, Jorge; Gómez Calderón, Óscar; Melle Hernández, Sonia; Laurenti, MarcoThe stunning optical properties of upconverting nanoparticles (UCNPs) have inspired promising biomedical technologies. Nevertheless, their transfer to aqueous media is often accompanied by intense luminescence quenching, partial dissolution by water, and even complete degradation by molecules such as phosphates. Currently, these are major issues hampering the translation of UCNPs to the clinic. In this work, a strategy is developed to coat and protect β-NaYF4 UCNPs against these effects, by growing a hydrophobic polymer shell (HPS) through miniemulsion polymerization of styrene (St), or St and methyl methacrylate mixtures. This allows one to obtain single core@shell UCNPs@HPS with a final diameter of ≈60–70 nm. Stability studies reveal that these HPSs serve as a very effective barrier, impeding polar molecules to affect UCNPs optical properties. Even more, it allows UCNPs to withstand aggressive conditions such as high dilutions (5 μg mL−1), high phosphate concentrations (100 mm), and high temperatures (70 °C). The physicochemical characterizations prove the potential of HPSs to overcome the current limitations of UCNPs. This strategy, which can be applied to other nanomaterials with similar limitations, paves the way toward more stable and reliable UCNPs with applications in life sciences.Item Radiation emission from an asymmetric quantum dot coupled to a plasmonic nanostructure(Journal of Optics, 2016) Antón Revilla, Miguel Ángel; Carreño Sánchez, Fernando; Gómez Calderón, Óscar; Melle Hernández, Sonia; Cabrera Granado, EduardoWe propose a scheme for controlling the absorption and RFS of a quantum dot (QD) with broken inversion symmetry interacting with a plasmonic nanostructure. The QD is described as a two-level atom-like system with a permanent dipole moment in the excited state. A linearly polarized laser field drives the optical transition of the QD and produces localized surface plasmons in the MNP. The influence of plasmonic effects between the nanoparticle and the dot is analyzed using the Green tensor method. We found terahertz (THz) emission in the resonance fluorescence spectrum when the laser frequency lies above the transition frequency. The position and strength of the THz peaks is controlled by means of the dot-nanoparticle separation. The quantum nature of the emitted THz photons is analyzed by evaluating the second-order fluorescence intensity correlation function. We found a periodic alternation of photon bunching and anti-bunching with a period that depends on the polarization of the driving field.Item Oligonucleotide sensor based on magnetic capture and photoligation of upconverting nanoparticles in solid surfaces(Journal of colloid and interface science, 2021) Méndez González, Diego; Silva Ibáñez, Pedro Pablo; Valiente Dies, Fernando; Gómez Calderón, Óscar; Mendez González, Juan Luis; Laurenti, Marco; Egatz-Gómez, Ana; Díaz García, Elena; Rubio Retama, Jorge; Melle Hernández, SoniaIn this work, we present a luminescence platform that can be used as point of care system for determining the presence and concentration of specific oligonucleotide sequences. This sensor exhibited a limit of detection as low as 50 fM by means of: i) the use of single-stranded DNA (ssDNA) functionalized magnetic microparticles that captured and concentrated ssDNA-upconverting nanoparticles (ssDNA-UCNPs) on a solid support, when the target sequence (miR-21-5p DNA-analogue) was in the sample, and ii) a photoligation reaction that covalently linked the ssDNA-UCNPs and the ssDNA magnetic microparticles, allowing stringent washes. The presented sensor showed a similar limit of detection when the assays were conducted in samples containing total miRNA extracted from human serum, demonstrating its suitability for detecting small specific oligonucleotide sequences under real-like conditions. The strategy of combining UCNPs, magnetic microparticles, and photoligation reaction provides new insight into low-cost, rapid, and ultra-sensitive detection of oligonucleotide sequences.Item Exploring the Origin of the Thermal Sensitivity of Near-Infrared-II Emitting Rare Earth Nanoparticles(Applied Materials and Interfaces, 2023) Hamraoui, Khouloud; Torres Vera, Vivian Andrea; Zabala Gutiérrez, Irene; Casillas Rubio, Alejandro; Alqudwa Fattouh, Mohammed; Benayas, Antonio; Marín, Riccardo; Natile, Marta María; Manso Silván, Miguel; Rubio Zuazo, Juan; Jaque, Daniel; Melle Hernández, Sonia; Gómez Calderón, Óscar; Rubio Retama, Benito JorgeRare-earth doped nanoparticles (RENPs) are attracting increasing interest in materials science due to their optical, magnetic, and chemical properties. RENPs can emit and absorb radiation in the second biological window (NIR-II, 1000-1400 nm) making them ideal optical probes for photoluminescence (PL) in vivo imaging. Their narrow emission bands and long PL lifetimes enable autofluorescence-free multiplexed imaging. Furthermore, the strong temperature dependence of the PL properties of some of these RENPs makes remote thermal imaging possible. This is the case of neodymium and ytterbium co-doped NPs that have been used as thermal reporters for in vivo diagnosis of, for instance, inflammatory processes. However, the lack of knowledge about how the chemical composition and architecture of these NPs influence their thermal sensitivity impedes further optimization. To shed light on this, we have systematically studied their emission intensity, PL decay time curves, absolute PL quantum yield, and thermal sensitivity as a function of the core chemical composition and size, active-shell, and outer-inert-shell thicknesses. The results revealed the crucial contribution of each of these factors in optimizing the NP thermal sensitivity. An optimal active shell thickness of around 2 nm and an outer inert shell of 3.5 nm maximize the PL lifetime and the thermal response of the NPs due to the competition between the temperature-dependent back energy transfer, the surface quenching effects, and the confinement of active ions in a thin layer. These findings pave the way for a rational design of RENPs with optimal thermal sensitivity.Item Boosting the Near-Infrared Emission of Ag2S Nanoparticles by a Controllable Surface Treatment for Bioimaging Applications(ACS Applied Materials & Interfaces, 2022) 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, Benito 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.Item 10-Fold Quantum Yield Improvement of Ag2S Nanoparticles by Fine Compositional Tuning(ACS Applied materials and interfaces, 2020) Ortega Rodríguez, Alicia; Shen, Yingli; Zabala Gutiérrez, Irene; Santos, Harrison D. A.; Torres Vera, Vivian Andrea; Ximedes, Erving; Villaverde Cantizano, Gonzalo; Lifante, José; Gerke, Christoph; Fernández Monsalve, Nuria; Gómez Calderón, Óscar; Melle Hernández, Sonia; Marqués Hueso, José; Méndez González, Diego; Laurenti, Marco; Jones, Callum M. S.; López Romero, Juan Manuel; Contreras Cáceres, Rafael; Jaque García, Daniel; Rubio Retama, Benito Jorge; Garma Pons, SantiagoAg2S semiconductor nanoparticles (NPs) are near-infrared luminescent probes with outstanding properties (good biocompatibility, optimum spectral operation range, and easy biofunctionalization) that make them ideal probes for in vivo imaging. Ag2S NPs have, indeed, made possible amazing challenges including in vivo brain imaging and advanced diagnosis of the cardiovascular system. Despite the continuous redesign of synthesis routes, the emission quantum yield (QY) of Ag2S NPs is typically below 0.2%. This leads to a low luminescent brightness that avoids their translation into the clinics. In this work, an innovative synthetic methodology that permits a 10-fold increment in the absolute QY from 0.2 up to 2.3% is presented. Such an increment in the QY is accompanied by an enlargement of photoluminescence lifetimes from 184 to 1200 ns. The optimized synthetic route presented here is based on a fine control over both the Ag core and the Ag/S ratio within the NPs. Such control reduces the density of structural defects and decreases the nonradiative pathways. In addition, we demonstrate that the superior performance of the Ag2S NPs allows for high-contrast in vivo bioimaging. .