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RL1: Sustainable Energy Conversion & Storage Systems

In the field of organic photovoltaics (PV), an alternative spectral splitting device concept, called RAINBOW, has been proposed, in which various individual junctions with cascading bandgaps are laid side by side. Each lateral sub-cell receives a fraction of the solar spectrum that matches the main absorption band of the given semiconductor. For a two-junction tandem it was already shown that this geometry can lead to a relative improvement in efficiency of ca. 50% with respect to the best sub-cell. In addition, a patented multi-purpose spectrum-on-demand light source (SOLS) has been developed, for which the EmErgEnt'23 Prize of the Clúster de l'Energia Eficient de Catalunya (CEEC) was awarded. This spectral shaper illumination device is expected to accelerate material screening and device optimization for emergent PV technologies.  Regarding complex oxides (e.g. La0.7Sr0.3MnO3) for PV applications, the chemical synthesis of thin films has been further developed for the fabrication of p-type transparent conducting electrodes and the role of sacrificial-layer composition has been studied for the realization of free-standing, flexible oxide membranes.

Soft nanoimprint lithography has been successfully employed to assemble versatile hybrid perovskite nanocrystals (NCs) into 2D-chiral metasurfaces, which exhibit remarkable asymmetry factors of 0.16 for the emission of circularly polarized light. This scalable approach to produce chiral luminescent thin films paves the way for the seamless production of bright chiral light sources.

Regarding thermal transport, the methodology of contactless frequency-domain thermoreflectance (FDTR) has been further extended to measure the in-plane thermal diffusivity of anisotropic materials, using a spatial offset between the 1D optical heat source and the probe beam. This method has been patented, resulting in a proof-of-concept project and the signing of a co-development contract with LINSEIS, a leading European company in the manufacture of commercial thermal-transport setups.

Battery research has a focus on synthesis and characterization of electrode materials for both Li-ion and post-Li ion batteries. Most recent work includes the study of Prussian Blue Analogues for Mg and Ca batteries and efforts on operando and synchrotron based techniques in collaboration with ALBA, where a joint laboratory has been established in the framework of the PTI Transener+. Organic positive electrodes are excellent low-cost, sustainable alternatives to inorganic materials and as such, polyimide was tested in mono and divalent cells, obtaining improved electrochemical performances in Mg-based electrolytes. Furthermore, wireless bipolar electrochemistry was successfully used to generate a substantial decrease in resistance of energy storage devices.

Considering laser-based materials processing techniques, especial efforts were made for increasing the technological readiness level (one industrial secret was registered). Besides, new approaches such as reactive inverse matrix-assisted pulsed-laser evaporation (RIMAPLE) and liquid phase laser synthesis, were advanced for the production of complex hybrid photo-catalysts for solar-based wastewater treatment and water-splitting hydrogen generation.

2D-chiral metasurfaces fabricated using nanoimprint lithography to produce chiral gammadion arrays with perovskite NCs

Mendoza-Carreño, José; Molet, Pau; Otero-Martínez, Clara; Alonso, María Isabel; Polavarapu, Lakshminarayana; Mihi, Agustín

Advanced Materials 2023, 35, 2210477.


The production of chiral perovskites has become an active field of research for its promising applications in optics, chemistry, or biology. Typically, chiral halide perovskites are obtained by the incorporation of different chiral moieties in the material. Unfortunately, these chemically modified perovskites have demonstrated moderate values of chiral photoluminescence (PL) so far. Here, a general and scalable approach is introduced to produce chiral PL from arbitrary nanoemitters assembled into 2D-chiral metasurfaces. The fabrication via nanoimprinting lithography employs elastomeric molds engraved with chiral motifs covering millimeter areas that are used to pattern two types of unmodified colloidal perovskite nanocrystal (NC) inks: green-emissive CsPbBr3 and red-emissive CsPbBr1I2. The perovskite 2D-metasurfaces exhibit remarkable PL dissymmetry factors (glum) of 0.16 that can be further improved up to glum of 0.3 by adding a high-refractive-index coating on the metasurfaces.

2D-chiral metasurfaces fabricated using nanoimprint lithography to produce chiral gammadion arrays with perovskite NCs

Gibert-Roca, Martí; Casademont-Viñas, Miquel; Liu, Quan; Vandewal, Koen; Goñi, Alejandro R.; Campoy-Quiles, Mariano

Advanced Materials 2023, 2212226


While multi-junction geometries have the potential to boost the efficiency of organic solar cells, the experimental gains yet obtained are still very modest. This work proposes an alternative spectral splitting device concept in which various individual semiconducting junctions with cascading bandgaps are laid side by side, thus the name RAINBOW. Each lateral sub-cell receives a fraction of the spectrum that closely matches the main absorption band of the given semiconductor. Simulations are used to develop design rules to identify the important material and device properties of each RAINBOW sub-cell. With the aid of a custom-built setup that generates spectrally spread sunlight on demand, the simulations are experimentally validated, showing that this geometry can lead to a reduction in thermalization losses and an improvement in light harvesting, which results in a relative improvement in efficiency of 46.6% with respect to the best sub-cell. Finally, a working proof-of-concept monolithic device consisting of two sub-cells deposited from solution on the same substrate is fabricated, thus demonstrating the feasibility and the potential of the RAINBOW solar cell concept.

2D-chiral metasurfaces fabricated using nanoimprint lithography to produce chiral gammadion arrays with perovskite NCs

Salles, Pol; Machado, Pamela; Yu, Pengmei; Coll, Mariona

Chemical Communications 2023, 59, 13820-13830


Oxides offer unique physical and chemical properties that inspire rapid advances in materials chemistry to design and nanoengineer materials compositions and implement them in devices for a myriad of applications. Chemical deposition methods are gaining attention as a versatile approach to develop complex oxide thin films and nanostructures by properly selecting compatible chemical precursors and designing an accurate cost-effective thermal treatment. Here, upon describing the basics of chemical solution deposition (CSD) and atomic layer deposition (ALD), some examples of the growth of chemically-deposited functional complex oxide films that can have applications in energy and electronics are discussed. The suitability of these techniques to prepare freestanding membranes of complex oxides is presented, which can significantly expand their applications.

2D-chiral metasurfaces fabricated using nanoimprint lithography to produce chiral gammadion arrays with perovskite NCs

Xu, Kai; Guo, Jiali; Raciti, Grazia; Goñi, Alejandro R.; Alonso, M. Isabel; Borrisé, Xavier; Zardo, Ilaria; Campoy-Quiles, Mariano; Reparaz, Juan Sebastián

International Journal of Heat and Mass Transfer 2023, 214, 124376


We present an innovative contactless method suitable to study in-plane thermal transport based on beam-offset frequency-domain thermoreflectance using a 1D heat source with uniform power distribution. Advantages of the 1D source, as compared to typically used point-like heat sources, are: (i) A slower spatial decay of the temperature field in the direction perpendicular to the line-shaped heat source, allowing to probe the temperature field at larger distances from the heater, hence, enhancing the sensitivity to in-plane thermal transport; (ii) the frequency range of interest is typically < 100 kHz. This rather low frequency range allows the study of materials without the need of a metallic transducer and with almost no influence of the penetration depth of the pump and probe beams on the thermal phase lag. We also show that for the case of a harmonic thermal excitation source, the phase lag between the thermal excitation and thermal response of the sample exhibits a linear dependence with their spatial offset, where the slope is proportional to the inverse of the thermal diffusivity of the material.

2D-chiral metasurfaces fabricated using nanoimprint lithography to produce chiral gammadion arrays with perovskite NCs

Black, Ashley P.; Sorrentino, Andrea; Fauth, François; Yousef, Ibraheem; Simonelli, Laura; Frontera, Carlos; Ponrouch, Alexandre; Tonti, Dino; Palacín, M. Rosa

Chemical Science 2023, 14, 1641-1665.


Synchrotron radiation based techniques are powerful tools for battery research and allow probing a wide range of length scales, with different depth sensitivities and spatial/temporal resolutions. Operando experiments enable characterization during functioning of the cell and are thus a precious tool to elucidate the reaction mechanisms taking place. In this perspective, the current state of the art for the most relevant techniques (scattering, spectroscopy, and imaging) is discussed together with the bottlenecks to address, either specific for application in the battery field or more generic. Given the recent evolution in the operando experimentation, accelerated progress is expected in the years to come, which should in turn foster battery performance improvements.

2D-chiral metasurfaces fabricated using nanoimprint lithography to produce chiral gammadion arrays with perovskite NCs

Ma, Zheng; Fuentes-Rodriguez, Laura; Tan, Zhengwei; Pellicer, Eva; Abad, Llibertat; Herrero-Martín, Javier; Menéndez, Enric; Casañ-Pastor, Nieves; Sort, Jordi.

Nature Communications 2023, 14, 6486.


Modulation of magnetic properties through voltage-driven ion motion and redox processes, i.e., magneto-ionics, is a unique approach to control magnetism with electric field for low-power memory and spintronic applications. So far, magneto-ionics has been achieved through direct electrical connections to the actuated material. Here we evidence that an alternative way to reach such control exists in a wireless manner. Induced polarization in the conducting material immersed in the electrolyte, without direct wire contact, promotes wireless bipolar electrochemistry, an alternative pathway to achieve voltage-driven control of magnetism based on the same electrochemical processes involved in direct-contact magneto-ionics. These results represent a fundamental breakthrough that may inspire future device designs for applications in bioelectronics, catalysis, neuromorphic computing, or wireless communications.

RL2: Superconducting Materials for Emerging Technologies

This Research Line is devoted to deploy unique know-how in superconducting materials and their use in emerging areas of energy, efficient ICT, high energy physics and astrophysics. In particular, our effort is concentrated in three main aspects. Firstly, in developing high-throughput, low-cost growth methods for Coated Conductors (CC) with engineered properties to approach theoretical limits. Also, in investigating superconducting electronic functionalities based on controlling properties of cuprates for ICT and impelling ultrasensitive Transition Edge Sensors (TES) as single photon and phonon detectors. Finally, in customizing CC materials for adequate integration in large scale systems (energy and high energy physics).

Our breakthrough in the development of the Transient Liquid Assisted growth (TLAG) process of cuprates at 100-1000 nm/s growth rates is now fully exploited in the in-situ growth platform at ALBA synchrotron, including the analysis of compositional gradient samples also in collaboration with Kyushu University. Now we have extended the feasibility of this approach to films prepared by Pulsed Laser Deposition, additionally to Chemical Solution Deposition. Also, new emerging ideas were initiated for its use in superconducting joints also involving differentiated oxygenation studies to reach large vortex pinning in the overdoped state.

In the investigation of electronic functionalities, nonlinear optical signatures of quantum phase transitions in the high-temperature superconductor YBCO have been investigated through magneto-transport and high harmonic generation technologies. Manipulation of the superconducting order parameter and electromigration effects were explored in cuprate high-temperature superconductors. In addition, in the framework of the European CHIST-ERA project, on-chip magnetic metasurfaces with efficient control of magnetic fields have been explored for boosting the sensitivity and efficiency of magnetic sensors and functional devices

Besides, in 2023 we worked on electrothermal modelling and noise analysis of TES for X-ray detection, as well as on determining their transition mechanisms. Also, within a project aimed at developing TESs for low-mass dark matter direct detection we started optimization of W films with very low Tc, and worked on the understanding of the decay processes suffered by the created phonons prior to their detection by the TES.

Our scouting activities in customization of CC has led to identified the best architecture to increase the electrical grid protection against short circuits by using surface modified CC in superconducting devices. Additionally, our consolidated collaboration with CERN in the development of low surface impedance superconducting coatings has expanded to high gradient electric fields and high magnetic field studies for accelerators and dark matter search.

Field quality and surface resistance studies of a superconducting REBa2Cu3O7−x - Cu hybrid coating for the FCC beam screen

Telles, G.; Romanov, A.; Calatroni, S.; Granados, X.; Puig, T.; Gutierrez, J.Nature Communications 2023, 14, 6486.

RE(=Y, Gd, Eu)Ba2Cu3O7−x  proposed as a low-surface impedance coating for the beam screen of a circular collider. Persistent currents in the superconductor will degrade the magnetic field homogeneity inside the beam chamber. We have explored the possibility of using a highly conductive hybrid coating made of Cu and REBa2Cu3O7−x. This decreases the surface impedance when compared to that of pure copper, while maintaining high magnetic field quality inside the beam screen chamber.

Transient Liquid Assisted Growth of Superconducting YBa2Cu3O7-x Films Based on Pulsed Laser Deposition

Queraltó, A.; Sieger, M.; Gupta, K.; Meledin, A.; Barusco, P.; Saltarelli, L.; de Palau, M.; Granados, X.; Obradors, X.; Puig, T.

Investigation of the integration of transient liquid-assisted growth (TLAG) approach for epitaxial YBa2Cu3O7−x (YBCO) films by physical deposition methodologies. Highly flat and amorphous YBCO precursor films were deposited by PLD at temperatures below 400 °C on single-crystalline SrTiO3 (STO) and LaMnO3 (LMO)/STO.

Microscale Metasurfaces for On-Chip Magnetic Flux Concentration

Fourneau, E., Arregi, J. A., Barrera, A., Nguyen, N. D., Bending, S., Sanchez, A., Uhlíř, V., Palau, A., Silhanek, A. V.

The effects of downscaling magnetic metamaterials for on-chip integration is investigated. The influence of the non-linear magnetic response of the ferromagnetic components, their magnetic irreversibility, the formation of magnetic domains, as well as the effects of geometry and size of the devices are scrutinized.

A Sulfurization method for creating the buffer-layers Current Flow Diverter architecture in REBa2Cu3O7 coated conductors

Barusco, P.; Giguere, J.; Lacroix, C.; Sirois, F.; Granados, X.; Puig, T.; Obradors, X.

The current flow diverter (CFD) is a known concept that has proven to effectively reduce the probability of destructive hot spots in REBa2Cu3O7 coated conductors (CCs) by boosting the normal zone propagation velocity. The implementation of this concept requires additional steps in a fabrication process that is already complex and has struggled to find a simple reel-to-reel fabrication method.

RL3: Oxides for New Generation Electronics

Researchers of the line have progressed in the understanding of the stabilization of the ferroelectric phase of HfO2, a key material in the spotlight of the memories industry. It has been scrutinized the role of stress and strain effects on the formed polymorphs and the ferroelectric polarization of epitaxial HfO2 thin films (FIGURE 1). The conclusion is that stress has a critical influence on the stabilization of the metastable orthorhombic phase and ferroelectric polarization. On the contrary, the direct effects of lattice deformation on the ferroelectric polarization are much smaller than those caused by variations in the orthorhombic phase content.

In the context of flexoelectricity, members of RL3 have provided a method to calculate the in-plane polarization response of a two-dimensional crystal to flexural deformations from first principles. It is found that a specific class of 2D crystals with D3d symmetry is endowed with a topologically nontrivial response, where simple ripple patterns can lead to a rich variety of in-plane polarization textures, including vortices, antivortices, monopoles and periodic arrangements thereof.

Light-matter interactions may be a gateway to enhanced functionality in materials. In this regard, we have investigated the photovoltaic response in ferroelectrics. Depending on the relative orientation of the light polarization and ferroelectric polarization direction, the response may display a characteristic oscillatory behavior, whose amplitude is directly related to the electronic structure of the material, the so-called: bulk photovoltaic effect (BPE). In particular, in LuMnO3 thin films, we have uncovered a large BPE-like photoresponsivity in the visible range and proposed a method to disregard spurious light-polarization contributions.

We have also investigated the subtle interplay between internal degrees of freedom in manganites, leading to complex and exotic ordered phases. In particular, we have studied three successive structural/electronic phase transitions that produce distinct charge and orbital order states in the Pr(Sr0.1Ca0.9)2Mn2O7 Ruddlesden-Popper compound. A full analysis in terms of symmetry-adapted modes allowed to identify the irreducible representations and distortion modes condensing at each charge order phase. Secondary modes were identified that transform antiferrodistortive distorted phases into a ferrodistortive structure compatible with improper ferroelectricity by trilinear coupling.

Researchers in the line have also used direct visualization and spectroscopy of the atomic structure of nominally stoichiometric Yttrium iron garnet (YIG) thin films. The experiments reveal the occurrence of Y-excess octahedral antisite defects. Notably, the saturation magnetization is higher than the bulk value, in consistency with the suppression of magnetic moment in the minority octahedral sublattice by the observed antisite defects. Analysis of elemental concentration profiles across the substrate-film interface suggests that the Y-excess is originated from unbalanced cationic interdiffusion during the early growth stages.

Researchers at RL3 have also explored spin-to-charge conversion phenomena within heterostructures of transition metal oxides (TMO) and normal metals (NM), a crucial area for advancing spintronics. Specifically, they investigated La2/3Sr1/3MnO3/SrIrO3 (LSMO/SIO) heterostructures, prepared both in-situ and ex-situ with the aim to tailor interfacial features, using RF sputtering. Measurements of the inverse spin Hall effect (ISHE) revealed the significant influence of interfacial characteristics on spin injection efficiency. Although ISHE voltage values were modest, they enabled the determination of the spin Hall angle of SIO (θSH ≈ 1.1% at T = 250 K), comparable to the well-established Py/Pt system. This suggests SIO holds promise as a spin-Hall material.

Finally, RL3 has developed perpendicularly magnetized epitaxial terbium iron garnet ultrathin films grown by magnetron sputtering onto single crystal garnet substrates. Members of RL3 have achieved highly tunable magnetic properties and sizeable spin transport across its interface with platinum, promising for spintronics applications. transition metal oxides for spintronics.

Disentangling stress and strain effects in ferroelectric HfO2.

Tingfeng Song, Veniero Lenzi, José P. B. Silva, Luís Marques, Ignasi Fina, Florencio Sánchez, Applied Physics Reviews 10,
041415 (2023)

Remanent polarization (Pr) of ferroelectric hafnia films as a function of the out-of-plane lattice parameter d(111). The linear Pr - d(111) dependences are consequence of the correlation between content of ferroelectric phase and strain. The comparison of Pr - d(111) dependences for films on SrTiO3(001) (cyan region) and Si(001) (yellow region) reflects the little direct effect of strain on polarization.

In-Plane Flexoelectricity in Two-Dimensional D3d Crystals.

Matteo Springolo, Miquel Royo, and Massimiliano Stengel Phys. Rev. Lett. 131, 236203 (2023)

A periodic sinusoidal deformation with threefold symmetry (top) induces the emergence of a hexagonal lattice of clockwise polarization vortices (bottom) in the D_3d monolayer.

Untwining polar contributions from light-polarization dependent photovoltaic response of LuMnO3-based ferroelectric capacitors.

Yunwei Sheng, Huan Tan, Alberto Quintana, Mario Villa , Jaume Gázquez, Ignasi Fina, and Josep Fontcuberta. Acta Materialia 245 (2023) 118601

a) High resolution STEM image of a LuMnO3 epitaxial film on a Pt layer. Inset shows experimental arrangement to measure dependence of the photocurrent on the polarization of an impinging laser beam. b) Light polarization dependence photocurrent (JSC, top) and open circuit voltage (VCO, bottom) measured in presence of bulk photovoltaic effect (BPE). c) Experimental dependence of the VCO on JSC, measured when varying the laser power and the light polarization as indicated. The different slope is taken as fingerprint of the presence of BPE.

Three charge-ordered phases in bilayered Pr(Sr0.1Ca0.9)2Mn2O7 compound: From antiferrodistortive to ferrodistortive structures.

J. Blasco, V. Cuartero, S. Lafuerza, J. L. García Muñoz, F. Fauth and G. Subías. Physical Review B 109, 024111

Crystal structures of the successive charge-order (CO) phases for Pr(Sr0.1Ca0.9)2Mn2O7, with respectively two (ap × 2bp × cp, Pbnm), three (2ap × bp × cp, Am2m) and four (2ap × bp × cp, Pn21m) nonequivalent Mn sites. (bottom) Representation of the atomic shifts (focused on a single bilayer) produced by the secondary distortion modes DT1 and GM5− at the ferroelectric CO2 phase. A trilinear coupling among rotation (X2+), tilt (X3−) and ferroelectric (GM5−) distortions can be operational in CO3.

Antisite Defects and Chemical Expansion in Low-damping, High-magnetization Yttrium Iron Garnet Films.

Jose Santiso; Carlos García; Cristian Romanque; Loïc Henry; Nicolas Bernier; Núria Bagués; José Manuel Caicedo; Manuel Valvidares; Felip Sandiumenge ChemNanoMat 2023, 9, e202200495

Unveiling the impact of unbalanced interdiffusion at the (111) Gd3Ga5O12/Y3Fe5O12 epitaxial interface on the net magnetic moment of Y3Fe5O12 by antisite defect formation.

Spin-to-Charge Conversion in All-Oxide La2/3Sr1/3MnO3/SrIrO3 Heterostructures

Sergi Martin-Rio, Zorica Konstantinovic, Alberto Pomar, Lluis Balcells, Javier Pablo-Navarro, M. Ricardo Ibarra, Cesar Magén, Narcis Mestres, Carlos Frontera, and Benjamin Martínez. ACS Appl. Mater. Interfaces 2023, 15, 37038−37046

The study of La2/3Sr1/3MnO3/SrIrO3 (LSMO/SIO) heterostructures shows successful spin injection into SIO layers using spin pumping. It is shown that interfacial features play a crucial role in spin injection. High-resolution imaging reveals structurally clean interfaces, but compositional analysis shows some diffusion of La and Mn species into the first SIO layers, which may affect spin transmission. Even spin mixing conductance is lower than in traditional systems, like permalloy (Py)/Pt, inverse spin Hall effect (ISHE) measurements allow to detect clear ISHE voltage signals and estimate the spin Hall angle (SH) of SIO that turns out to be similar to the well-known Py/Pt system. This suggests that SIO is a promising material as a spin current detector.

Sputtered terbium iron garnet films with perpendicular magnetic anisotropy for spintronic applications.

S. Damerio & C. O. Avci, J. Appl. Phys. 133, 073902 (2023)

Ferrimagnetic garnets with perpendicular anisotropy have attracted increasing attention in spintronics thanks to their desirable properties, such as low magnetization, ultrafast switching, and domain wall motion. In this work, we have shown that a typical ferrimagnetic garnet, TbIG, can be grown by magnetron sputtering, a technologically feasible method for fabricating thin films, with tunable magnetic properties highly relevant for spintronic devices.

RL4: Tuneable and Low Cost Molecular Electronics

In RL4 efforts have been placed towards the development of novel electronic platforms based on molecular materials.

Organic radicals have been in depth investigated since these materials offer appealing magnetic and optoelectronic properties, which can be exploited for different uses that range from sensing, as quantum memory qubits or as molecular wires/rectifiers. For instance, the temperature-dependent fluorescence of organic nanoparticles, based on the dual emission, generated by monomer and excimer species have been investigated. It was found that the excimer emission intensity of the studied materials decreased with increasing temperatures whereas the monomer emission was almost independent and could be used as an internal reference. These radical nanoparticles could then be used to sense temperature changes at the nano-microscale, which was proved in in vivo experiments with Caenorhabditis elegans (C. elegans) worms.

Additionally, solid-state metal/radical monolayer/semiconductor (Si) junctions have been fabricated. These molecular-based devices show a characteristic diode behaviour, revealing a high rectification. The system was also interrogated under irradiation, evidencing that at the wavelength where the photon energy is close to the band gap of the radical there is a clear enhancement of the photoresponse.

Other molecules that have been investigated in molecular junctions are norbornadiene derivatives capped with thioether and thioester anchor groups. It has been found that norbornadiene capped with thioacetate and tert-butyl groups exhibited higher conductance compared to methyl thioether. Computational results for electron transport across these junctions aligned closely with the experimental findings. However, in terms of junction stability, the methyl thioether-capped system was the most resilient. These findings advance both the design and understanding of functional molecular systems in the realm of single-molecule electronics.

In terms of large-area electronics, we have been working on improving the device performance of organic field-effect transistors. Doping methodologies have been applied in order to reduce the contact resistance and the density of charge traps and, hence, improve the device mobility. This has been realised by using iodine as dopant or also by doping locally the device contacts. Insights into the impact of the doping methodologies on the electrical and structural properties of the materials/devices have been elucidated at the macroscale and at the nanoscale employing Kelvin Probe Force Microscopy.

Finally, electrolyte-gated organic field-effect transistors (EGOFETs) are also being investigated for the development of sensors. In particular, we have demonstrated a robust pH sensor able to respond in the pH range 1–10. This was realized by exploiting the pH-dependent supramolecular host–guest complexation of imidazole/β-cyclodextrin (β-CD). The sensing protocol performed consisted in incubating magnetic nanoparticles functionalized with β-CD with imidazole solutions at different pHs and trapping them in a magnetic carbon gate electrode.

Ratiometric Nanothermometer Based on a Radical Excimer for In Vivo Sensing

D. Blasi, N. Gonzalez-Pato, X. Rodriguez Rodriguez, I. Diez-Zabala, S. Y. Srinivasan, N. Camarero, O. Esquivias, M. Roldán, J. Guasch, A. Laromaine, P. Gorostiza, J. Veciana, Imma Ratera Small 2023, 19, 2207806

The temperature-dependent fluorescence of organic nanoparticles is designed, synthesized, and studied based on the dual emission, generated by monomer and excimer species, of the tris(2,4,6-trichlorophenyl)methyl radical (TTM) doping organic nanoparticles (TTMd-ONPs), made of optically neutral tris(2,4,6-trichlorophenyl)methane (TTM-αH), acting as a matrix.

Stable organic radical for enhancing metal-monolayer-semiconductor junction performance.

J. A. De Sousa, R. Pfattner, D. Gutierrez, K. Jutglar, S. T. Bromley, J. Veciana, C. Rovira, M. Mas-Torrent, B. Fabre, N. Crivillers, ACS Appl. Mater. & Interf. 2023, 15, 4635.

The preparation of monolayers based on an organic radical and its diamagnetic counterpart has been pursued on hydrogen-terminated silicon surfaces. The functional monolayers have been investigated as solid-state metal/monolayer/semiconductor (MmS) junctions showing a characteristic diode behavior which is tuned by the electronic characteristics of the organic molecule.

Exploring the impact of select anchor groups for norbornadiene/quadricyclane single-molecule switches.

S. Ghasemi, L. Ornago, Z. Liasi, M. B. Johansen, T. J. von Buchwald, A. E. Hillers-Bendtsen, S. van der Poel, H. Holzel, Z. Wang, F. M. A. Noa, L. Ohrstrom, K. V. Mikkelsen, H. S. J. van der Zant, S. Lara-Avila K. Moth-Poulsen.
J. Mater. Chem. C, 2023, 11, 15412

To achieve the ultimate limit of device miniaturization, it is necessary to have a comprehensive understanding of the structure–property relationship in functional molecular systems used in single-molecule electronics. This study reports the synthesis and characterization of a novel series of norbornadiene derivatives capped with thioether and thioester anchor groups.

Synergistic effect of solvent vapor annealing and chemical doping for achieving high-performance organic field-effect transistors with ideal electrical characteristics.

J. Li, A. Babuji, L. Fijahi, A. M. James, R. Resel, T. Salzillo, R. Pfattner, C. Ocal, E. Barrena, M. Mas-Torrent,
ACS Appl. Mater. & Interf. 2023, 15, 5521.

Contact resistance and charge trapping are two key obstacles, often intertwined, that negatively impact on the performance of organic field-effect transistors (OFETs) by reducing the overall device mobility and provoking a nonideal behavior. Here, we expose organic semiconductor (OSC) thin films based on blends of 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT-C8) with polystyrene (PS) to (i) a CH3CN vapor annealing process, (ii) a doping I2/water procedure, and (iii) vapors of I2/CH3CN to simultaneously dope and anneal the films.

pH Sensor based on supramolecular host–guest interactions and an organic field-effect transistor with a magnetic carbon gate electrode.

A. Tamayo, A. Campos-Lendinez, J. Muñoz, N. Crivillers, M. Mas-Torrent.
Chemistry of Materials. 2023, 5, 21, 9257.

A robust electrolyte-gated organic field-effect transistor (EGOFET) able to respond to pH in the range 1–10 is reported. This is realized by exploiting the pH-dependent supramolecular host–guest complexation of imidazole/β-cyclodextrin (β-CD).

RL5: Bioactive Materials for Therapy and Diagnosis

With the objective to increase the selectivity, efficiency and safety of the nanomedicines and generate a better understanding of their interaction with biological entities, RL5 has generate scientific and technological knowledge through the design, synthesis and processing of new materials of interest to biomedical companies and clinical groups for improved diagnosis and treatment of diseases.

RL5 also counted with transversal key enabling technologies for the development of the proposed objectives, such as the in-vivo C.elegans models, theoretical models and atomistic simulations, cell culture lab and a soft material lab belonging to the ICTS NANBIOSIS. The spin-off company Nanomol  Technologies have participated in the upscaling of some of the developed nanomaterials (e.g. nanovesicles for drug delivery).

Arrhythmic Effects Evaluated on Caenorhabditis elegans: The Case of Polypyrrole Nanoparticles

Sumithra Yasaswini Srinivasan, Pilar Alvarez Illera, Dmytro Kukhtar, Núria Benseny-Cases, Julián Cerón, Javier Álvarez, Rosalba I. Fonteriz, Mayte Montero, and Anna Laromaine

Multicellular organisms such as the Caenorhabditis elegans (C. elegans) can bridge the gap between in vitro and vertebrate testing as they can provide extensive information on systemic toxicity. Since the nematodes’ pharynx shares similarities with the human heart, we assessed the general and pharyngeal effects of drugs and polypyrrole nanoparticles (Ppy NPs) using C. elegans.The evaluation of FDA-approved drugs, such as Propranolol and Racepinephrine reproduced the arrhythmic behavior reported in humans and supported the use of this small animal model. Consequently, Ppy NPs were evaluated due to their research interest in cardiac arrhythmia treatments. The NPs’ biocompatibility was confirmed by assessing survival, growth and development, reproduction, and transgenerational toxicity in C. elegans. Interestingly, the NPsincreased the pharyngeal pumping rate of C. elegans in two slow-pumping mutant strains.

Moreover, the NPs increased the pumping rate over time, which sustained up to a day post-excretion. Thus, evaluating arrhythmic effects in C. elegans offers a simple system to test drugs and nanoparticles, as elucidated through Ppy NPs.Moreover, it has been demonstrate that  Conductive Bacterial Nanocellulose-Polypyrrole Patches Promote Cardiomyocyte Differentiation (ACS Appl. Bio Mater. 2023, 6, 7, 2860–2874; DOI:

Stable nanovesicles formed by intrinsically planar bilayers

Mariana Köber, Sílvia Illa-Tuset, Lidia Ferrer-Tasies, Evelyn Moreno-Calvo, Witold I. Tatkiewicz, Natascia Grimaldi, David Piña, Alejandro Pérez Pérez, Vega Lloveras, José Vidal-Gancedo, Donatella Bulone, Imma Ratera, Jan Skov Pedersen, Dganit Danino, Jaume Veciana, Jordi Faraudo, Nora Ventosa

Quatsome nanovesicles, formed through the self-assembly of cholesterol (CHOL) and cetyltrimethylammonium bromide (CTAB) in water, have shown long-term stability in terms of size and morphology, while at the same time exhibiting high CHOL-CTAB intermolecular binding energies. Coarse-grain molecular dynamics simulations were used to investigate the molecular organization in the vesicle membrane, and the characteristics of the simulated vesicle were corroborated with experimental data obtained by cryo–electron microscopy, small- and wide-angle X-ray scattering, and multi-angle static light scattering. CHOL/CTAB quatsomes fulfill the requisites of thermodynamically stable nanovesicles, but they do not exhibit the classical membrane curvature induced by a composition asymmetry between the bilayer leaflets, like catanionic nanovesicles. Instead, CHOL/CTAB quatsomes are formed through the association of intrinsically planar bilayers in a faceted vesicle with defects, indicating that distortions in the organization and orientation of molecules can play a major role in the formation of thermodynamically stable nanovesicles.

Moreover, Quatsomes with squarine dye has been probe to be an effective photosensitizer for Photodynamic Therapy (PDT). This strategy allows using a therapeutic squaraine concentration that is 100 times lower than the concentration of free squaraine usually employed in PDT.  (Pharmaceutics 202315(3), 902

Ratiometric Nanothermometer Based on a Radical Excimer for In Vivo Sensing

Davide Blasi, Nerea Gonzalez-Pato, Xavier Rodriguez Rodriguez, Iñigo Diez-Zabala, Sumithra Yasaswini Srinivasan, Núria Camarero, Oriol Esquivias, Mònica Roldán, Judith Guasch, Anna Laromaine, Pau Gorostiza, Jaume Veciana, Imma Ratera

Ratiometric fluorescent nanothermometers with near-infrared emission play an important role in in vivo sensing since they can be used as intracellular thermal sensing probes with high spatial resolution and high sensitivity, to investigate cellular functions of interest in diagnosis and therapy, where current approaches are not effective. Herein, the temperature-dependent fluorescence of organic nanoparticles is designed, synthesized, and studied based on the dual emission, generated by monomer and excimer species, of the tris(2,4,6-trichlorophenyl)methyl radical (TTM) doping organic nanoparticles (TTMd-ONPs), made of optically neutral  tris(2,4,6-trichlorophenyl)methane (TTM-αH), acting as a matrix.

The excimer emission intensity decreases with increasing temperatures whereas the monomer emission is almost independent and can be used as an internal reference. TTMd-ONPs show a great temperature sensitivity (3.4% K−1 at 328 K) and a wide temperature response at ambient conditions with excellent reversibility and high colloidal stability. In vivo thermometry experiments in Caenorhabditis elegans (C. elegans) worms show that TTMd-ONPs can locally monitor internal body temperature changes with spatio-temporal resolution and high sensitivity, offering multiple applications in the biological nanothermometry field.Moreover, these nanothermometer showed Two-Photon Excitation and Emission in the Biological Transparency Window allowing deeper penetration and Temperature Monitoring of Biological Tissues demonstrating their potential as NIR nanothermometers for bio applications.(Small Methods 2023, 2301060.  DOI:

Lithium halide filled carbon nanocapsules: Paving the way towards lithium neutron capture therapy (LiNCT)

Gil Gonçalves, Stefania Sandoval, Marina Llenas, Belén Ballesteros, Tatiana Da Ros, Silva Bortolussi, Laura Cansolino, Cinzia Ferrari, Ian Postuma, Nicoletta Protti, Manuel Melle-Franco, Saverio Altieri, Gerard Tobías-Rossell

Neutron capture therapy (NCT) is a form of radiotherapy that exploits the potential of some specific isotopes to capture thermal neutrons and subsequently yield high linear energy transfer (LET) particles, suitable for cancer treatment. Recently, relevant technological improvements have been made in terms of accelerators as suitable neutron sources for NCT at hospitals. However, low selective delivery of current drugs to cancer cells remains as the main challenge for successful clinical application of NCT. This work presents an innovative and previously unexplored approach for the design of nanotherapeutic NCT agents.

Herein, a new concept based on carbon nanomaterials that seal 6Li active NCT nuclides is investigated. The 6Li active species are located in the inner cavity of the nanocarrier (carbon nanohorns or carbon nanotubes) and therefore, completely protected from the biological environment, avoiding toxicity and degradation. After encapsulation of the active cargo, the external surface of the nanocarrier is modified for improved biocompatibility. The developed 6Li-filled carbon nanohorns offered the possibility to explore 6Li compounds as active NCT agents by delivering therapeutic doses to cancer cells. We envisage that nanoencapsulation of 6Li can trigger the successful development and implementation of Lithium Neutron Cancer Therapy (LiNCT).

Moreover, it has also been developed a A Potential Boron NCT Agent that Selectively Suppresses High-Grade Glioma: In Vitro and in Vivo Exploration (Mol. Pharmaceutics 2023, 20, 5, 2702–2713; DOI:

Supercritical CO2 Synthesis of Porous Metalloporphyrin Frameworks: Application in Photodynamic Therapy

Márta Kubovics, Oriol Careta, Oriol Vallcorba, Guillermo Romo-Islas, Laura Rodríguez, Jose A. Ayllón, Concepción Domingo, Carme Nogués, and Ana M. López-Periago

A series of porous metalloporphyrin frameworks with four metal complexes, M(hfac)2 M = Cu(II), Zn(II), Co(II), and Ni(II) (hfac: 1,1,1,5,5,5-hexafluoroacetylacetonate), were obtained  using supercritical CO2 (scCO2) as a solvent. A layering technique from a mixture of organic solvents was used to crystallize high-quality crystals of the Co(II) based MOF,. The Zn(II)-based MOF was selected as a potential photodynamic therapy drug in the SKBR-3 tumoral cell line showing outstanding performance. This MOF resulted to be nontoxic, but after 15 min of irradiation at 630 nm, using either 1 or 5 μM concentration of the product, almost 70% of tumor cells died after 72 h.

Moreover, a Facile, fast and green synthesis of a highly porous  calcium-syringate bioMOF has also been developed showing outstanding surface area >1000 m2 g−1, and a micropore diameter of 1.4 nm close to mesopore values. Collectively, these data establish CaSyr-1 as one of     the most porous bioMOFs reported to date, encapsulating triple therapeutic entities;  involving bioactive Ca2+, syringic acid and an impregnated drug. (Inorg. Chem. Front., 2023,10, 2165-2173; DOI:

Ce1−xZrxO2 nanoparticles in bacterial cellulose, bio-based composites with self-regenerating antioxidant capabilities

Bacterial cellulose (BC) is an emerging biopolymer with ever-widening uses in the biomedical field due to its purity, mechanical stability, conformability, moisture control, and biocompatibility. In the wet form, its highly porous nanofibrillar structure and abundant surface hydroxyl groups enable the functionalisation of BC with            inorganic nanoparticles (NPs), granting the material additional purposive capabilities.As oxidative stress caused by reactive oxygen species (ROS) negatively affects various cellular structures, the functionalisation of BC with CeO2 NPs, known antioxidants, is pursued in this work to achieve composites capable of minimising inflammation and tissue damage. We report on low-temperature in situ syntheses of CeO2 NPs in BC enabling the formation of BC–CeO2 composites that exhibit self-regenerating antioxidant properties, recording the highest %DPPH scavenging per unit mass of NPs among the BC–Ce1−xZrxO2 studied systems.

Moreover, BC  Cell-Laden 3D Hydrogels of Type I Collagen Incorporating Bacterial Nanocellulose Fibers have been developed. These collagen hydrogels reinforced  with BCf might emerge as a promising platform for 3D in vitro organ modeling, tissue-engineering applications, and suitable to conduct fundamental mechanobiology studies.

Fluorescent and Magnetic Radical Dendrimers as Potential Bimodal Imaging Probes

Songbai Zhang, Vega Lloveras, Yufei Wu, Juan Tolosa, Joaquín C García-Martínez, José Vidal-Gancedo

Dual or multimodal imaging probes have emerged as powerful tools that improve detection sensitivity and accuracy in disease diagnosis by imaging techniques. Two imaging techniques that are complementary and do not use ionizing radiation are magnetic resonance imaging (MRI) and optical fluorescence imaging (OFI). Herein, we prepared metal-free organic species based on dendrimers with magnetic and fluorescent properties as proof-of-concept of bimodal probes for potential MRI and OFI applications. We used oligo(styryl)benzene (OSB) dendrimers core that are fluorescent on their own, and TEMPO organic radicals anchored on their surfaces, as the magnetic component. The new dendrimers present two properties: on one hand, they are paramagnetic and show the ability to generate contrast by MRI in vitro, and, on the other hand, they also show fluoresce emission. This is a remarkable result since it is one of the very few cases of macromolecules with bimodal magnetic and fluorescent properties using organic radicals as the magnetic probe.