Non-invasive paper-based sensors containing rare-earth-doped nanoparticles for the detection of D-glucose.

Today, diabetes mellitus is one of the most common diseases that affects the population on a worldwide scale. Patients suffering from this disease are required to control their blood-glucose levels several times a day through invasive methods such as piercing their fingers. Our NaGdF: 5% Er, 3% Nd nanoparticles demonstrate a remarkable ability to detect D-glucose levels by analysing alterations in their red-to-green ratio, since this sensitivity arises from the interaction between the nanoparticles and the OH groups present in the D-glucose molecules, resulting in discernible changes in the emission of the green and red bands.

Novel Characterization Techniques for Multifunctional Plasmonic-Magnetic Nanoparticles in Biomedical Applications.

In the rapidly emerging field of biomedical applications, multifunctional nanoparticles, especially those containing magnetic and plasmonic components, have gained significant attention due to their combined properties. These hybrid systems, often composed of iron oxide and gold, provide both magnetic and optical functionalities and offer promising avenues for applications in multimodal bioimaging, hyperthermal therapies, and magnetically driven selective delivery. This paper focuses on the implementation of advanced characterization methods, comparing statistical analyses of individual multifunctional particle properties with macroscopic properties as a way of fine-tuning synthetic methodologies for their fabrication methods.

First-Principles Calculations of Magnetite (FeO) above the Verwey Temperature by Using Self-Consistent DFT + + .

In this report, we have used the DFT + + approach, an extension of the DFT + approach that takes into account both on-site and intersite interactions, to simulate structural, magnetic, and electronic properties together with the Fe and O K-edge XAS spectra of FeO above the Verwey temperature (). Moreover, we compared the simulated XAS spectra with experimental XAS data. We examined both orthogonalized and nonorthogonalized atomic orbital projectors and compared DFT + + to DFT, DFT + , and HSE as a hybrid functional.

Amplitude-Resolved Single Particle Spectrophotometry: A Robust Tool for High-Throughput Size Characterization of Plasmonic Nanoparticles.

Plasmonic nanoparticles have a wide range of applications in science and industry. Despite the numerous synthesis methods reported in the literature over the last decades, achieving precise control over the size and shape of large nanoparticle populations remains a challenge. Since variations in size and shape significantly affect the plasmonic properties of nanoparticles, accurate metrological techniques to characterize their morphological features are essential.

Antibacterial Films of Silver Nanoparticles Embedded into Carboxymethylcellulose/Chitosan Multilayers on Nanoporous Silicon: A Layer-by-Layer Assembly Approach Comparing Dip and Spin Coating.

The design and engineering of antibacterial materials are key for preventing bacterial adherence and proliferation in biomedical and household instruments. Silver nanoparticles (AgNPs) and chitosan (CHI) are broad-spectrum antibacterial materials with different properties whose combined application is currently under optimization. This study proposes the formation of antibacterial films with AgNPs embedded in carboxymethylcellulose/chitosan multilayers by the layer-by-layer (LbL) method.

Exploring the Origin of the Thermal Sensitivity of Near-Infrared-II Emitting Rare Earth Nanoparticles.

Rare-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.

First-principles calculations of hematite (α-FeO) by self-consistent DFT+U+V.

Owing to the confined Fe-3d orbitals and self-interaction error of exchange-correlation functionals, approximate DFT fails to describe iron oxides electronic structure and magnetic properties accurately. Hybrid DFT or DFT + U can solve these problems, but the former is expensive, and the latter only considers on-site interactions. Here, we used DFT + U + V, a DFT + U extension including inter-site interactions, to simulate the structural, magnetic, and electronic properties, along with Fe and O K-edge XAS spectra of α-FeO.

Coatings of Cyclodextrin/Citric-Acid Biopolymer as Drug Delivery Systems: A Review.

In the early 2000s, a method for cross-linking cyclodextrins (CDs) with citric acid (CTR) was developed. This method was nontoxic, environmentally friendly, and inexpensive compared to the others previously proposed in the literature. Since then, the CD/CTR biopolymers have been widely used as a coating on implants and other materials for biomedical applications.

Surface characterization of alkane viral anchoring films prepared by titanate-assisted organosilanization.

Studies of virus adsorption on surfaces with optimized properties have attracted a lot of interest, mainly due to the influence of the surface in the retention, orientation and stability of the viral capsids. Besides, viruses in whole or in parts can be used as cages or vectors in different areas, such as biomedicine and materials science. A key requirement for virus nanocage application is their physical properties, i.

Tribochemically driven dehydrogenation of undoped sodium alanate under room temperature.

An application of mechanical energy was explored as a new non-thermal method to drive H emission from undoped sodium alanate at room temperature. It was found that mild rubbing of NaAlH pellets under vacuum led to intensive and almost instantaneous gas emission. The dominating species in the emitted gases was H (>99%).

Size characterization of plasmonic nanoparticles with dark-field single particle spectrophotometry.

Plasmonic nanoparticles are widely used in multiple scientific and industrial applications. Although many synthesis methods have been reported in the literature throughout the last decade, controlling the size and shape of large populations still remains as a challenge. As size and shape variations have a strong impact in their plasmonic properties, the need to have metrological techniques to accurately characterize their morphological features is peremptory.

Phonon Structure, Infra-Red and Raman Spectra of LiMnO by First-Principles Calculations.

The layer-structured monoclinic LiMnO is a key material, mainly due to its role in Li-ion batteries and as a precursor for adsorbent used in lithium recovery from aqueous solutions. In the present work, we used first-principles calculations based on density functional theory (DFT) to study the crystal structure, optical phonon frequencies, infra-red (IR), and Raman active modes and compared the results with experimental data. First, LiMnO powder was synthesized by the hydrothermal method and successively characterized by XRD, TEM, FTIR, and Raman spectroscopy.

Boosting the Near-Infrared Emission of AgS Nanoparticles by a Controllable Surface Treatment for Bioimaging Applications.

AgS 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, AgS 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.

Hydrothermal control of the lithium-rich LiMnO phase in lithium manganese oxide nanocomposites and their application as precursors for lithium adsorbents.

Lithium manganese oxides (LMOs) are key materials due to their role in Li-ion batteries and lithium recovery from aqueous lithium resources. In the present work, we investigated the effect of the crystallization temperature on the formation by hydrothermal synthesis of LMO nanocomposites with high Li/Mn ratios. It is demonstrated that LMOs with a high Li/Mn ratio can be formed by systematically favoring the lithium-rich layered monoclinic phase (LiMnO) in a mixture of monoclinic and spinel crystalline phases.

Fabrication and characterization of nanostructured porous silicon-silver composite layers by cyclic deposition: dip-coating vs spin-coating.

Composites of nanostructured porous silicon and silver (nPSi-Ag) have attracted great attention due to the wide spectrum of applications in fields such as microelectronics, photonics, photocatalysis and bioengineering, Among the different methods for the fabrication of nanostructured composite materials, dip and spin-coating are simple, versatile, and cost-effective bottom-up technologies to provide functional coatings. In that sense, we aimed at fabricating nPSi-Ag composite layers. Using nPSi layers with pore diameter of 30 nm, two types of thin-film techniques were systematically compared: cyclic dip-coating (CDC) and cyclic spin-coating (CSC).

Plasma Fabrication and SERS Functionality of Gold Crowned Silicon Submicrometer Pillars.

Sequential plasma processes combined with specific lithographic methods allow for the fabrication of advanced material structures. In the present work, we used self-assembled colloidal monolayers as lithographic structures for the conformation of ordered Si submicrometer pillars by reactive ion etching. We explored different discharge conditions to optimize the Si pillar geometry.

Sol-Gel-Deposited Ti-Doped ZnO: Toward Cell Fouling Transparent Conductive Oxides.

Ti-doped ZnO thin films were obtained with the aim of tailoring ZnO film bioadhesiveness and making the optoelectronic properties of ZnO materials transferable to biological environments. The films were prepared on silicon substrates by sol-gel spin-coating and subsequent annealing. A Ti-O segregation limits the ZnO crystallite growth and creates a buffer out-layer.

Porous Silicon Bragg Reflector and 2D Gold-Polymer Nanograting: A Route Towards a Hybrid Optoplasmonic Platform.

Photonic and plasmonic systems have been intensively studied as an effective means to modify and enhance the electromagnetic field. In recent years hybrid plasmonic-photonic systems have been investigated as a promising solution for enhancing light-matter interaction. In the present work we present a hybrid structure obtained by growing a plasmonic 2D nanograting on top of a porous silicon distributed Bragg reflector.

Loading the dice: The orientation of virus-like particles adsorbed on titanate assisted organosilanized surfaces.

The organization of virus-like particles (VLPs) on surfaces is a relevant matter for both fundamental and biomedical sciences. In this work, the authors have tailored surfaces with different surface tension components aiming at finding a relationship with the affinity of the different geometric/surface features of icosahedral P22 VLPs. The surfaces have been prepared by titanate assisted organosilanization with glycidyloxy, amino, and perfluoro silanes.

Visible Light Assisted Organosilane Assembly on Mesoporous Silicon Films and Particles.

Porous silicon (PSi) is a versatile matrix with tailorable surface reactivity, which allows the processing of a range of multifunctional films and particles. The biomedical applications of PSi often require a surface capping with organic functionalities. This work shows that visible light can be used to catalyze the assembly of organosilanes on the PSi, as demonstrated with two organosilanes: aminopropyl-triethoxy-silane and perfluorodecyl-triethoxy-silane.

Controlling the Epitaxial Growth of BiTe, BiTe, and BiTe Pure Phases by Physical Vapor Transport.

BiTe is a well-studied material because of its thermoelectric properties and, recently, has also been studied as a topological insulator. However, it is only one of several compounds in the Bi-Te system. This work presents a study of the physical vapor transport growth of Bi-Te material focused on determining the growth conditions required to selectively obtain a desired phase of the Bi-Te system, i.

Biofouling Properties of Nitroxide-Modified Amorphous Carbon Surfaces.

Amorphous carbon films exhibit attractive optical and surface properties. In this work, modified amorphous carbon films incorporating nitroxide groups (α-CNO) have been obtained by searching for a condensed analogue to classical soft antifouling materials. Thin films deposited by reactive magnetron sputtering in air discharges at varying power conditions were characterized by ellipsometry, atomic force microscopy, and water contact angle.

Nanostructured porous silicon: the winding road from photonics to cell scaffolds - a review.

For over 20 years, nanostructured porous silicon (nanoPS) has found a vast number of applications in the broad fields of photonics and optoelectronics, triggered by the discovery of its photoluminescent behavior in 1990. Besides, its biocompatibility, biodegradability, and bioresorbability make porous silicon (PSi) an appealing biomaterial. These properties are largely a consequence of its particular susceptibility to oxidation, leading to the formation of silicon oxide, which is readily dissolved by body fluids.

Nanotopography enhanced mobility determines mesenchymal stem cell distribution on micropatterned semiconductors bearing nanorough areas.

Surface micropatterns are relevant instruments for the in vitro analysis of cell cultures in non-conventional planar conditions. In this work, two semiconductors (Si and TiO2) have been micropatterned by combined ion-beam/chemical-etching processes leading to selective areas bearing nanorough features. A preferential affinity of human mesenchymal stem cells (hMSCs) for planar areas versus nanotopographic ones is observed.

Nanostructured porous silicon-mediated drug delivery.

Introduction: The particular properties of nanostructured porous silicon (nanoPS) make it an attractive material for controlled and localized release of therapeutics within the body, aiming at increased efficacy and reduced risks of potential side effects. Since this is a rapidly evolving field as a consequence of the number of research groups involved, a critical review of the state of the art is necessary.

Areas Covered: In this work, the most promising and successful applications of nanoPS in the field of drug delivery are reviewed and discussed.