Magnetically Responsive Enzyme and Hydrogen-Bonded Organic Framework Biocomposites for Biosensing.

The one-pot synthesis of multicomponent hydrogen-bonded organic framework (HOF) biocomposites is reported. The co-immoblization of enzymes and magnetic nanoparticles (MNPs) into the HOF crystals yielded biocatalysts (MNPs-enzyme@BioHOF-1) with dynamic localization properties. Using a permanent magnet, it is possible to separate the MNPs-enzyme@BioHOF-1 particles from a solution.

Multimode vibrational coupling across the insulator-to-metal transition in 1T-TaS2 in THz cavities.

The use of optical cavities on resonance with material excitations allows controlling light-matter interaction in both the regimes of weak and strong coupling. We study here the multimode vibrational coupling of low energy phonons in the charge-density-wave material 1T-TaS2 across its insulator-to-metal phase transition. For this purpose, we embed 1T-TaS2 into THz Fabry-Pérot cryogenic cavities tunable in frequency within the spectral range of the vibrational modes of the insulating phase and track the linear response of the coupled phonons across the insulator-to-metal transition.

Ordered Transfer from 3D-Oriented MOF Superstructures to Polymeric Films: Microfabrication, Enhanced Chemical Stability, and Anisotropic Fluorescent Patterns.

Films and patterns of 3D-oriented metal-organic frameworks (MOFs) afford well-ordered pore structures extending across centimeter-scale areas. These macroscopic domains of aligned pores are pivotal to enhance diffusion along specific pathways and orient functional guests. The anisotropic properties emerging from this alignment are beneficial for applications in ion conductivity and photonics.

Water sensitivity of heteroepitaxial Cu-MOF films: dissolution and re-crystallization of 3D-oriented MOF superstructures.

3D-oriented metal-organic framework (MOF) films and patterns have recently emerged as promising platforms for sensing and photonic applications. These oriented polycrystalline materials are typically prepared by heteroepitaxial growth from aligned inorganic nanostructures and display anisotropic functional properties, such as guest molecule alignment and polarized fluorescence. However, to identify suitable conditions for the integration of these 3D-oriented MOF superstructures into functional devices, the effect of water (gaseous and liquid) on different frameworks should be determined.

All-dielectric metaoptics for the compact generation of double-ring perfect vector beams.

Perfect vortices, whose ring profile is independent of the topological charge, play a key role in telecommunications and particle micro-manipulation. In this work, we report the compact generation of a new kind of double-ring perfect vortices, called double-ring perfect vector beams, by exploiting dual-functional silicon metaoptics. In particular, we develop and test a new paradigm to generate those beams with the possibility of selecting different topological charges between the two rings.

Cavity-mediated thermal control of metal-to-insulator transition in 1T-TaS.

Placing quantum materials into optical cavities provides a unique platform for controlling quantum cooperative properties of matter, by both weak and strong light-matter coupling. Here we report experimental evidence of reversible cavity control of a metal-to-insulator phase transition in a correlated solid-state material. We embed the charge density wave material 1T-TaS into cryogenic tunable terahertz cavities and show that a switch between conductive and insulating behaviours, associated with a large change in the sample temperature, is obtained by mechanically tuning the distance between the cavity mirrors and their alignment.

Silicon metaoptics for the compact generation of perfect vector beams in the telecom infrared.

Perfect vortices have attracted considerable attention as orbital angular momentum (OAM) beams with customizable ring-like intensity distribution. More recently, the non-separable combination of perfect vortices with opposite OAMs and spins, yielding so-called perfect vector beams, has further expanded their applications in the fields of optical manipulation and imaging, high-resolution lithography, and telecommunications. Exploiting the combined manipulation of dynamic and geometric phases using silicon anisotropic metaunits, here we present the design, fabrication, and characterization of novel, to the best of our knowledge, dielectric metaoptics for the compact generation of perfect vector beams in the telecom infrared using a single metasurface.

Implication of the double-gating mode in a hybrid photon counting detector for measurements of transient heat conduction in GaAs/AlAs superlattice structures.

Understanding and control of thermal transport in solids at the nanoscale are crucial in engineering and enhance the properties of a new generation of optoelectronic, thermoelectric and photonic devices. In this regard, semiconductor superlattice structures provide a unique platform to study phenomena associated with phonon propagations in solids such as heat conduction. Transient X-ray diffraction can directly probe atomic motions and therefore is among the rare techniques sensitive to phonon dynamics in condensed matter.

Dual-functional metalenses for the polarization-controlled generation of focalized vector beams in the telecom infrared.

The availability of static tiny optical devices is mandatory to reduce the complexity of optical paths that typically use dynamic optical components and/or many standard elements for the generation of complex states of light, leading to unprecedented levels of miniaturization and compactness of optical systems. In particular, the design of flat and integrated optical elements capable of multiple vector beams generation with high resolution in the visible and infrared range is very attractive in many fields, from life science to information and communication technology. In this regard, we propose dual-functional transmission dielectric metalenses that act simultaneously on the dynamic and geometric phases in order to manipulate independently right-handed and left-handed circularly polarized states of light and generate focused vector beams in a compact and versatile way.

Half-wet nanomechanical sensors for cellular dynamics investigations.

Testing devices based on cell tracking are particularly interesting as diagnostic tools in medicine for antibiotics susceptibility testing and in vitro chemotherapeutic screening. In this framework, the application of nanomechanical sensors has attracted much attention, although some crucial aspects such as the effects of the viscous damping, when operating in physiological conditions environment, still need to be properly solved. To address this problem, we have designed and fabricated a nanomechanical force sensor that operates at the interface between liquid and air.

Unraveling the timescale of the structural photo-response within oriented metal-organic framework films.

Fundamental knowledge on the intrinsic timescale of structural transformations in photo-switchable metal-organic framework films is crucial to tune their switching performance and to facilitate their applicability as stimuli-responsive materials. In this work, for the first time, an integrated approach to study and quantify the temporal evolution of structural transformations is demonstrated on an epitaxially oriented DMOF-1-on-MOF film system comprising azobenzene in the DMOF-1 pores (DMOF-1/AB). We employed time-resolved Grazing Incidence Wide-Angle X-Ray Scattering measurements to track the structural response of the DMOF-1/AB film upon altering the length of the azobenzene molecule by photo-isomerization (-to-, 343 nm; -to-, 450 nm).

Water-Air Interface to Mimic In Vitro Tumoral Cell Migration in Complex Micro-Environments.

The long-known role of cell migration in physiological and pathological contexts still requires extensive research to be fully understood, mainly because of the intricate interaction between moving cells and their surroundings. While conventional assays fail to capture this complexity, recently developed 3D platforms better reproduce the cellular micro-environment, although often requiring expensive and time-consuming imaging approaches. To overcome these limitations, we developed a novel approach based on 2D micro-patterned substrates, compatible with conventional microscopy analysis and engineered to create micro-gaps with a length of 150 µm and a lateral size increasing from 2 to 8 µm, where a curved water-air interface is created on which cells can adhere, grow, and migrate.

Atomic force spectroscopy-based essay to evaluate oocyte postovulatory aging.

Postovulatory aging is a process occurring in the mature (MII) oocyte leading the unfertilized ones to apoptosis. The optimal time window of fertility for different mammalian species after oocytes maturation depends on its timeliness: the higher the time elapsed from the accomplishment of the MII stage, the lower are the chances of fertilization and of development of a viable embryo. In the in vitro fertilization, the selection of competent oocytes for intracytoplasmic sperm injection (ICSI) is mostly made by the visual inspection of the MII oocyte morphology, which does not allow to determine the oocyte postovulatory age.

Multi-layered ZIF-coated cells for the release of bioactive molecules in hostile environments.

Metal-organic framework (MOF) coatings on cells enhance viability in cytotoxic environments. Here, we show how protective multi-layered MOF bio-composite shells on a model cell system (yeast) enhance the proliferation of living cells exposed to hostile protease-rich environments the dissolution of the shells and release of a protease inhibitor (antitrypsin).

Patterned Carboxymethyl-Dextran Functionalized Surfaces Using Organic Mixed Monolayers for Biosensing Applications.

The deposition of biomolecules on biosensing surface platforms plays a key role in achieving the required sensitivity and selectivity for biomolecular interactions analysis. Controlling the interaction between the surface and biomolecules is increasingly becoming a crucial design tool to modulate the surface properties needed to improve the performance of the assay and the detection outcome. Carboxymethyl-dextran (CMD) coating can be exploited to promote chemical grafting of proteins, providing a hydrophilic, bioinert, nonfouling surface and a high surface density of immobilized proteins.

Synchrotron Radiation Study of Gain, Noise, and Collection Efficiency of GaAs SAM-APDs with Staircase Structure.

In hard X-ray applications that require high detection efficiency and short response times, such as synchrotron radiation-based Mössbauer absorption spectroscopy and time-resolved fluorescence or photon beam position monitoring, III-V-compound semiconductors, and dedicated alloys offer some advantages over the Si-based technologies traditionally used in solid-state photodetectors. Amongst them, gallium arsenide (GaAs) is one of the most valuable materials thanks to its unique characteristics. At the same time, implementing charge-multiplication mechanisms within the sensor may become of critical importance in cases where the photogenerated signal needs an intrinsic amplification before being acquired by the front-end electronics, such as in the case of a very weak photon flux or when single-photon detection is required.

Tunable cryogenic terahertz cavity for strong light-matter coupling in complex materials.

We report here the realization and commissioning of an experiment dedicated to the study of the optical properties of light-matter hybrids constituted of crystalline samples embedded in an optical cavity. The experimental assembly developed offers the unique opportunity to study the weak and strong coupling regimes between a tunable optical cavity in cryogenic environment and low energy degrees of freedom, such as phonons, magnons, or charge fluctuations. We describe here the setup developed that allows for the positioning of crystalline samples in an optical cavity of different quality factors, the tuning of the cavity length at cryogenic temperatures, and its optical characterization with a broadband time domain THz spectrometer (0.

Energy Level Alignment at the Cobalt Phosphate/Electrolyte Interface: Intrinsic Stability vs Interfacial Chemical Reactions in 5 V Lithium Ion Batteries.

The intrinsic stability of the 5 V LiCoPO-LiCoPO thin-film (carbon-free) cathode material coated with MoO thin layer is studied using a comprehensive synchrotron electron spectroscopy in situ approach combined with first-principle calculations. The atomic-molecular level study demonstrates fully reversible electronic properties of the cathode after the first electrochemical cycle. The polyanionic oxide is not involved in chemical reactions with the fluoroethylene-containing liquid electrolyte even when charged to 5.

ZnO Thin Films Growth Optimization for Piezoelectric Application.

The piezoelectric response of ZnO thin films in heterostructure-based devices is strictly related to their structure and morphology. We optimize the fabrication of piezoelectric ZnO to reduce its surface roughness, improving the crystalline quality, taking into consideration the role of the metal electrode underneath. The role of thermal treatments, as well as sputtering gas composition, is investigated by means of atomic force microscopy and x-ray diffraction.

A novel free-electron laser single-pulse Wollaston polarimeter for magneto-dynamical studies.

Here, we report on the conceptual design, the hardware realization, and the first experimental results of a novel and compact x-ray polarimeter capable of a single-pulse linear polarization angle detection in the extreme ultraviolet photon energy range. The polarimeter is tested by performing time resolved pump-probe experiments on a NiFe Permalloy film at the M Ni edge at an externally seeded free-electron laser source. Comparison with similar experiments reported in the literature shows the advantages of our approach also in view of future experiments.

Perspectives of Microscopy Methods for Morphology Characterisation of Extracellular Vesicles from Human Biofluids.

Extracellular vesicles (EVs) are nanometric membranous structures secreted from almost every cell and present in biofluids. Because EV composition reflects the state of its parental tissue, EVs possess an enormous diagnostic/prognostic potential to reveal pathophysiological conditions. However, a prerequisite for such usage of EVs is their detailed characterisation, including visualisation which is mainly achieved by atomic force microscopy (AFM) and electron microscopy (EM).

µDrop: a system for high-throughput small-angle X-ray scattering measurements of microlitre samples.

An automatic sample changer system for measurements of large numbers of liquid samples - the µDrop Sample Changer - is presented. It is based on a robotic arm equipped with a pipetting mechanism, which is combined with a novel drop-based sample holder. In this holder a drop of liquid is suspended between two parallel plates by surface tension.

Nanostructured P3HT as a Promising SensingElement for Real-Time, Dynamic Detection ofGaseous Acetone.

The dynamic response of gas sensors based on poly(3-hexylthiophene) (P3HT) nanofibers(NFs) to gaseous acetone was assessed using a setup based on flow-injection analysis, aimed atemulating actual breath exhalation. The setup was validated by using a commercially available sensor.The P3HT NFs sensors tested in dynamic flow conditions showed satisfactory reproducibility down toabout 3.

Timing methodologies and studies at the FERMI free-electron laser.

Time-resolved investigations have begun a new era of chemistry and physics, enabling the monitoring in real time of the dynamics of chemical reactions and matter. Induced transient optical absorption is a basic ultrafast electronic effect, originated by a partial depletion of the valence band, that can be triggered by exposing insulators and semiconductors to sub-picosecond extreme-ultraviolet pulses. Besides its scientific and fundamental implications, this process is very important as it is routinely applied in free-electron laser (FEL) facilities to achieve the temporal superposition between FEL and optical laser pulses with tens of femtoseconds accuracy.