Fe/Au galvanic nanocells to generate self-sustained Fenton reactions without additives at neutral pH.

The generation of reactive oxygen species (ROS) the Fenton reaction has received significant attention for widespread applications. This reaction can be triggered by zero-valent metal nanoparticles by converting externally added HO into hydroxyl radicals (˙OH) in acidic media. To avoid the addition of external additives or energy supply, developing self-sustained catalytic systems enabling onsite production of HO at a neutral pH is crucial.

Near-IR Photoinduced Electrochemiluminescence Imaging with Structured Silicon Photoanodes.

Infrared (IR) imaging devices that convert IR irradiation (invisible to the human eye) to a visible signal are based on solid-state components. Here, we introduce an alternative concept based on light-addressable electrochemistry (i.e.

The efficient magneto-mechanical actuation of cancer cells using a very low concentration of non-interacting ferrimagnetic hexaferrite nanoplatelets.

Magneto-mechanical actuation (MMA) using the low-frequency alternating magnetic fields (AMFs) of magnetic nanoparticles internalized into cancer cells can be used to irreparably damage these cells. However, nanoparticles in cells usually agglomerate, thus greatly augmenting the delivered force compared to single nanoparticles. Here, we demonstrate that MMA also decreases the cell viability, with the MMA mediated by individual, non-interacting nanoparticles.

Enhanced Proliferation and Differentiation of Human Osteoblasts by Remotely Controlled Magnetic-Field-Induced Electric Stimulation Using Flexible Substrates.

With the progressive aging of the population, bone fractures are an increasing major health concern. Diverse strategies are being studied to reduce the recovery times using nonaggressive treatments. Electrical stimulation (either endogenous or externally applied electric pulses) has been found to be effective in accelerating bone cell proliferation and differentiation.

Modular Drug-Loaded Nanocapsules with Metal Dome Layers as a Platform for Obtaining Synergistic Therapeutic Biological Activities.

Multifunctional drug-loaded polymer-metal nanocapsules have attracted increasing attention in drug delivery due to their multifunctional potential endowed by drug activity and response to physicochemical stimuli. Current chemical synthesis methods of polymer/metal capsules require specific optimization of the different components to produce particles with precise properties, being particularly complex for Janus structures combining polymers and ferromagnetic and highly reactive metals. With the aim to generate tunable synergistic nanotherapeutic actuation with enhanced drug effects, here we demonstrate a versatile hybrid chemical/physical fabrication strategy to incorporate different functional metals with tailored magnetic, optical, or chemical properties on solid drug-loaded polymer nanoparticles.

All-Optical Electrochemiluminescence.

Electrochemiluminescence (ECL) is widely employed for medical diagnosis and imaging. Despite its remarkable analytical performances, the technique remains intrinsically limited by the essential need for an external power supply and electrical wires for electrode connections. Here, we report an electrically autonomous solution leading to a paradigm change by designing a fully integrated all-optical wireless monolithic photoelectrochemical device based on a nanostructured Si photovoltaic junction modified with catalytic coatings.

Efficient Tumor Eradication at Ultralow Drug Concentration via Externally Controlled and Boosted Metallic Iron Magnetoplasmonic Nanocapsules.

With the aim to locally enhance the efficacy of cancer nanotherapies, here we present metal iron based magnetoplasmonic drug-loaded nanocapsules (MAPSULES), merging powerful external magnetic concentration in the tumor and efficient photothermal actuation to locally boost the drug therapeutic action at ultralow drug concentrations. The MAPSULES are composed of paclitaxel-loaded polylactic--glycolic acid (PLGA) nanoparticles partially coated by a nanodome shape iron/silica semishell. The iron semishell has been designed to present a ferromagnetic vortex for incorporating a large quantity of ferromagnetic material while maintaining high colloidal stability.

Elastic Plasmonic-Enhanced Fabry-Pérot Cavities with Ultrasensitive Stretching Tunability.

The emerging stretchable photonics field faces challenges, like the robust integration of optical elements into elastic matrices or the generation of large optomechanical effects. Here, the first stretchable plasmonic-enhanced and wrinkled Fabry-Pérot (FP) cavities are demonstrated, which are composed of self-embedded arrays of Au nanostructures at controlled depths into elastomer films. The novel self-embedding process is triggered by the Au nanostructures' catalytic activity, which locally increases the polymer curing rate, thereby inducing a mechanical stress that simultaneously pulls the Au nanostructures into the polymer and forms a wrinkled skin layer.

Mechanochromic Detection for Soft Opto-Magnetic Actuators.

New multi-stimuli responsive materials are required in smart systems applications to overcome current limitations in remote actuation and to achieve versatile operation in inaccessible environments. The incorporation of detection mechanisms to quantify in real time the response to external stimuli is crucial for the development of automated systems. Here, we present the first wireless opto-magnetic actuator with mechanochromic response.

Hybrid Ni@ZnO@ZnS-Microalgae for Circular Economy: A Smart Route to the Efficient Integration of Solar Photocatalytic Water Decontamination and Bioethanol Production.

Water remediation and development of carbon-neutral fuels are a priority for the evermore industrialized society. The answer to these challenges should be simple, sustainable, and inexpensive. Thus, biomimetic-inspired circular and holistic processes combing water remediation and biofuel production can be an appealing concept to deal with these global issues.

Highly reduced ecotoxicity of ZnO-based micro/nanostructures on aquatic biota: Influence of architecture, chemical composition, fixation, and photocatalytic efficiency.

Developing efficient sunlight photocatalysts with enhanced photocorrosion resistance and minimal ecotoxicological effects on aquatic biota is critical to combat water contamination. Here, the role of chemical composition, architecture, and fixation on the ecotoxicological effects on microalgae of different ZnO and ZnO@ZnS based water decontamination photocatalysts was analyzed in depth. In particular, the ecotoxicological effects of films, nanoparticles and biomimetic micro/nano-ferns were carefully assessed by correlating the algae's viability to the Zn(II) release, the photocatalyst-microalgae interaction, and the production of reactive oxygen species (ROS).

Water-mediated photo-induced reduction of platinum films.

Platinum thin films activated ex situ by oxygen plasma become reduced by the combined effect of an intense soft X-ray photon beam and condensed water. The evolution of the electronic structure of the surface has been characterized by near-ambient-pressure photoemission and mimics the inverse two-step sequence observed in the electro-oxidation of platinum, i.e.

Precise Size Control of the Growth of FeO Nanocubes over a Wide Size Range Using a Rationally Designed One-Pot Synthesis.

The physicochemical properties of spinel oxide magnetic nanoparticles depend critically on both their size and shape. In particular, spinel oxide nanocrystals with cubic morphology have shown superior properties in comparison to their spherical counterparts in a variety of fields, like, for example, biomedicine. Therefore, having an accurate control over the nanoparticle shape and size, while preserving the crystallinity, becomes crucial for many applications.

Unraveling the Operational Mechanisms of Chemically Propelled Motors with Micropumps.

The development of effective autonomous micro- and nanomotors relies on controlling fluid motion at interfaces. One of the main challenges in the engineering of such artificial machines is the quest for efficient mechanisms to power them without using external driving forces. In the past decade, there has been an important increase of man-made micro- and nanomotors fueled by self-generated physicochemical gradients.

Simultaneous Local Heating/Thermometry Based on Plasmonic Magnetochromic Nanoheaters.

A crucial challenge in nanotherapies is achieving accurate and real-time control of the therapeutic action, which is particularly relevant in local thermal therapies to minimize healthy tissue damage and necrotic cell deaths. Here, a nanoheater/thermometry concept is presented based on magnetoplasmonic (Co/Au or Fe/Au) nanodomes that merge exceptionally efficient plasmonic heating and simultaneous highly sensitive detection of the temperature variations. The temperature detection is based on precise optical monitoring of the magnetic-induced rotation of the nanodomes in solution.

Photochemically Activated Motors: From Electrokinetic to Diffusion Motion Control.

Self-propelled micro/nanomotors that can transform chemical energy from the surrounding environment into mechanical motion are cutting edge nanotechnologies with potential applications in biomedicine and environmental remediation. These applications require full understanding of the propulsion mechanisms to improve the performance and controllability of the motors. In this work, we demonstrate that there are two competing chemomechanical mechanisms at semiconductor/metal (Si/Pt) micromotors in a pump configuration under visible light exposure.

Molecular inversion probe-based SPR biosensing for specific, label-free and real-time detection of regional DNA methylation.

DNA methylation has the potential to be a clinically important biomarker in cancer. This communication reports a real-time and label-free biosensing strategy for DNA methylation detection in the cancer cell line. This has been achieved by using surface plasmon resonance biosensing combined with the highly specific molecular inversion probe based amplification method, which requires only 50 ng of bisulfite treated genomic DNA.

Direct detection of protein biomarkers in human fluids using site-specific antibody immobilization strategies.

Design of an optimal surface biofunctionalization still remains an important challenge for the application of biosensors in clinical practice and therapeutic follow-up. Optical biosensors offer real-time monitoring and highly sensitive label-free analysis, along with great potential to be transferred to portable devices. When applied in direct immunoassays, their analytical features depend strongly on the antibody immobilization strategy.

Trends and challenges of refractometric nanoplasmonic biosensors: a review.

Motivated by potential benefits such as sensor miniaturization, multiplexing opportunities and higher sensitivities, refractometric nanoplasmonic biosensing has profiled itself in a short time span as an interesting alternative to conventional Surface Plasmon Resonance (SPR) biosensors. This latter conventional sensing concept has been subjected during the last decades to strong commercialization, thereby strongly leaning on well-developed thin-film surface chemistry protocols. Not surprisingly, the examples found in literature based on this sensing concept are generally characterized by extensive analytical studies of relevant clinical and diagnostic problems.

Sensing with magnetic dipolar resonances in semiconductor nanospheres.

In this work we propose two novel sensing principles of detection that exploit the magnetic dipolar Mie resonance in high-refractive-index dielectric nanospheres. In particular, we theoretically investigate the spectral evolution of the extinction and scattering cross sections of these nanospheres as a function of the refractive index of the external medium (next). Unlike resonances in plasmonic nanospheres, the spectral position of magnetic resonances in high-refractive-index nanospheres barely shifts as next changes.

Enhanced light extraction in ITO-free OLEDs using double-sided printed electrodes.

We show how nanoimprint lithographic techniques are particularly suited for the realization of OLED device structures. We tested them to realize nanopatterned metallic electrodes containing photonic crystals to couple the light out and plasmonic crystals showing extraordinary transmission. At similar current densities, a two-fold electroluminescence is achieved with devices having double-sided structured metallic electrodes as compared to a control OLED with an ITO anode.

All-optical phase modulation for integrated interferometric biosensors.

We present the theoretical and the experimental implementation of an all-optical phase modulation system in integrated Mach-Zehnder Interferometers to solve the drawbacks related to the periodic nature of the interferometric signal. Sensor phase is tuned by modulating the emission wavelength of low-cost commercial laser diodes by changing their output power. FFT deconvolution of the signal allows for direct phase readout, immune to sensitivity variations and to light intensity fluctuations.

Polypeptide folding-mediated tuning of the optical and structural properties of gold nanoparticle assemblies.

Responsive hybrid nanomaterials with well-defined properties are of significant interest for the development of biosensors with additional applications in tissue engineering and drug delivery. Here, we present a detailed characterization using UV-vis spectroscopy and small angle X-ray scattering of a hybrid material comprised of polypeptide-decorated gold nanoparticles with highly controllable assembly properties. The assembly is triggered by a folding-dependent bridging of the particles mediated by the heteroassociation of immobilized helix-loop-helix polypeptides and a complementary nonlinear polypeptide present in solution.

Guiding light in monolayers of sparse and random plasmonic meta-atoms.

Encouraged by the capacity of surface plasmons to confine and propagate electromagnetic fields, waveguiding concepts have been developed, including combinations of continuous metal films or ordered arrays of metal nanoparticles. So far, waveguiding in the latter systems has been based on near-field or diffractive coupling. Herein, we show that monolayers of sparse and disordered gold nanoparticles support a novel transverse-electric guided mode that, contrary to previous work, relies on the strong enhancement of the polarizability upon excitation of the nanoparticle LSPR, creating an effective refractive index sufficiently high to support light guidance over a large range of frequencies.