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All scientific publications in Area Science Park
Chirality Unlocks Sub-Terahertz Molecular Dynamics in Peptide Nanotubes
Abstract Low-frequency modes in the picosecond range play a key role in molecular recognition and biomolecular function. Here, we investigate how these dynamics at the interfaces of self-assembled peptide biomaterials relate to fine structural details of the supramolecular assembly. We resolve terahertz and mid-infrared modes in individual diphenylalanine nanotubes by nanoscale microspectroscopy, uncovering a direct correlation between supramolecular chirality, molecular arrangement, and picosecond dynamics at the nanotube-environment boundary. By combining THz and mid-IR nanoscopy with a multiscale strategy spanning single nanotubes and ensemble measurements, supported by density functional theory calculations, we access the intrinsic picosecond response of peptide assemblies beyond the limits of conventional microscopy and ensemble averaging. Heterochiral (D-L) nanotubes display sharp resonances, whereas homochiral (L-L) nanotubes exhibit a comparatively featureless sub-THz profile, revealing a clear chirality-dependent contrast. Mode assignments show that the heterochiral features are dominated by localized torsional and bending motions of phenyl rings relative to the peptide backbone. Overall, chirality-dependent THz fingerprints emerge as sensitive descriptors of peptide nanotube architecture, while low-frequency nanospectroscopy provides a route to interrogate biomaterial interfaces under biologically relevant conditions. Authors Rajat Kumar, Erica Scarel, Andrea Perucchi, Lisa Vaccari, Prasanta Kumar Datta, Francesco D’amico, Paola Di Pietro, Silvia Marchesan, Federica Piccirilli Journal ChemrXiv Publication date 11/03/2026 Consult the publication
Ultrafast Intermolecular Dynamics of Nanoconfined Water in Swollen Lipid Cubic Mesophases
Abstract Understanding the structure and dynamics of the hydrogen-bond network ofwater in topologically distinct swollen lipidic mesophases, is fundamental fortheir application in biomedical, pharmaceutical, and food science fields. Here,a positive and non-linear correlation between water hydrogen-bond dynamicsand interfacial water population is uncovered in inverse bicontinuous swollenmesophases across an extended temperature range (298–340 K). Particularly,small-angle X-ray scattering determines the mesophase’s structural features,uncovering a temperature-driven re-entrant phenomenon (reappearance) ofPn̄ 3m phase upon heating. This topologically rich environment, however, hasno detectable impact on the temperature dependence of the intermolecularmodes of water, as revealed by terahertz absorption spectroscopy. Specifically,these modes show distinct dynamics: the stretching mode exhibits longerlifetimes than the libration mode, yet with a higher temperature-dependence,with approximately two-fold lower Arrhenius activation energies. In contrast,both stretching and libration modes exhibit a monotonic decrease in lifetimewith increasing temperature, due to the increasing disruption of thehydrogen-bond network. Atomistic molecular dynamics simulations enablethe quantification of interfacial water population, which shows a positivecorrelation with intermolecular lifetimes in a nonlinear manner, revealing anon-additive coupling between interfacial water population and waterhydrogen-bond network dynamics within these systems. Authors Eva Zunzunegui-Bru, Serena Rosa Alfarano, Patrick Züblin, Laura Baraldi,Hendrik Vondracek, Federica Piccirilli, Lisa Vaccari, and Raffaele Mezzenga Journal Small Publication date 03/10/2025 Consult the publication
Broadband terahertz signatures and vibrations of Phe–Phe peptide and its fibrils
Abstract In recent years, peptide-based nanomaterials have gained significant attention in drug discovery due to their biocompatibility and promising functionality in biophysical processes. This current study employs terahertz (THz) spectroscopy and density functional theory (DFT) to investigate the vibrational properties of the phenylalanine dipeptide (Phe–Phe), a building block with notable self-assembling properties and potential applications in drug delivery and nanostructured biomaterials. The dynamics of proteins and biomolecules occurring on the picosecond timescale can be probed by THz spectroscopy and is closely related to their functionality. Here, we investigate the low-frequency vibrational modes of Phe–Phe under two different conditions, as crystalline commercial powder and post-self-assembled powder, in the 0.2–4 THz range. The refractive index of pure Phe–Phe, as evaluated from THz spectroscopy, is approximately 1.47, and the THz absorption peaks are observed at 0.55, 0.83, 1.13, 1.40, 1.68, 2.18, 2.71, 3.00, and 3.33 THz. Potential energy distribution (PED) analysis provides a detailed assignment of the observed modes and identifies characteristic vibrational features. The novel thin bi-layer approach for sample preparation employed here proved to be effective in terms of signal-to-noise ratio and in eliminating artifacts possibly originating from the host material. This combined experimental–computational approach not only offers valuable insights into the conformational flexibility and self-assembly potential of Phe–Phe, but also underscores the efficacy of THz spectroscopy and DFT analysis for studying the vibrational properties of peptides, with implications for biophysics, nanotechnology, and biochemistry. Moreover, this study highlights the impact of intermolecular interactions on the vibrational spectra by comparing crystalline powder and self-assembled peptide powder. Authors Rajat Kumar, Federica Piccirilli, Paola Di Pietro, Johannes Schmidt, Giovanni Birarda, Lisa Vaccari, Andrea Perucchi, Prasanta Kumar Datta Journal Analyst Publication date 24/04/2025 Consult the publication
Eco-friendly NaCl glycerol-based deep eutectic electrolyte for high-voltage electrochemical double layer capacitor
Abstract Herein, we propose eco-friendly electrolytes based on sodium chloride as a hydrogen bond acceptor and glycerol as a hydrogen bond donor, as alternatives to toxic, flammable and unsustainable electrolytes commonly used in electrochemical energy storage systems. By means of an in-depth multi-technique investigation, including Raman and FT-FIR spectroscopy, of the formulated electrolytes, we point out the effect of the structuring of the system on the transport and electrochemical properties. The 1 : 10 molar ratio mixture proves to be a deep eutectic solvent (DES), showing good room temperature ionic conductivity (0.186 mS cm−1) and electrochemical stability (≈3 V). When implemented as electrolyte in an activated-carbon electrochemical double layer capacitor, this DES exhibits superior performance compared to mixtures with different molar ratio and those containing ethylene glycol as the hydrogen bond donor, with a high operational voltage (2.6 V), a specific capacitance of 14.1 F g−1, and a remarkable cycling stability. These findings highlight the potential of glycerol-based DESs as alternative electrolytes for sustainable electrochemical energy storage applications. Authors Daniele Motta, Alessandro Damin, Hamideh Darjazi, Stefano Nejrotti, Federica Piccirilli, Giovanni Birarda, Claudia Barolo, Claudio Gerbaldi, Giuseppe Antonio Elia, Matteo Bonomo Journal Green Chemistry Publication date 31/03/2025 Consult the publication
Co-assembled supramolecular hydrogels: nano-IR sheds light on tripeptide assemblies
Abstract Supramolecular hydrogels composed of self-assembling short peptides are gaining momentum for enzyme mimicry. In particular, multicomponent systems that feature similar peptides with a self-assembling motif (e.g., Phe–Phe) and catalytic residues (e.g., His, Asp) offer a convenient approach to organize in space, functional residues that typically occur at enzymatic active sites. However, characterisation of these systems, and especially understanding whether the different peptides co-assemble or self-sort, is not trivial. In this work, we study two-component hydrogels composed of similar tripeptides and describe how nano-IR can reveal important details of their packing, thus demonstrating it to be a useful technique to characterise multicomponent, nanostructured gels. Authors Paola Alletto, Ana M. Garcia, Federica Piccirilli, Silvia Marchesan Journal Faraday Discussions Publication date 21/02/2025 Consult the publication
Striped Twisted State in the Orientational Epitaxy on Quasicrystals
Abstract The optimal “twisted” geometry of a crystalline layer on a crystal has long been known, but that on a quasicrystal is still unknown and open. We predict analytically that the layer equilibrium configuration will generally exhibit a nonzero misfit angle. The theory perfectly agrees with numerical optimization of a colloid monolayer on a quasiperiodic decagonal optical lattice. Strikingly different from crystal-on-crystal epitaxy, the structure of the novel emerging twisted state exhibits an unexpected stripe pattern. Its high anisotropy should reflect on the tribomechanical properties of this unconventional interface. Authors Nicola Manini, Mario Forzanini, Sebastiano Pagano, Marco Bellagente, Martino Colombo, Dario Bertazioli, Tommaso Salvalaggio, Andrea Vanossi, Davide Vanossi, Emanuele Panizon, Erio Tosatti, Giuseppe E. Santoro Journal Physical Review Letters Publication Date 12/02/2025 Consult the publication
CO2 and Temperature Induced Switching of a Flexible Metal–Organic Framework with Surface-Mounted Nanoparticles
Abstract Within the material family of metal–organic frameworks (MOFs) the subclass of flexible MOFs (flexMOFs) has attracted great attention, showing structural flexibility as a response to external stimuli such as guest adsorption, temperature, and pressure. Hybrid composites like nanoparticle (NP) loaded flexible MOFs, which stand to potentially combine advantageous properties of both are yet largely unexplored. Here the synthesis of flexMOFs with surface mounted nanoparticles, e. g. NP@Zn2(BME-bdc)2dabco composites (NP = Pt and SiO2 nanoparticles, BME-bdc2− = 2,5-bismethoxyethoxy-1,4-benzenedicarboxylate, dabco = 1,4-diazabicyclo[2.2.2]octane) is reported, studying the impact of nanoparticles on the stimulus-responsiveness of a flexMOF. It is shown that CO2 physisorption triggered flexibility of the MOF is retained and reversible for all NP@flexMOF composites. Additionally, it is observed that NPs stabilize the large pore state of the MOF, slightly increasing and shifting the switching pressure window. This effect is also observed during temperature-induced switching but Pt@flexMOF composites partially lose long-range order during the reversion to their narrow pore state, while attached SiO2 NPs allow for a fully reversible transition. These findings suggest that the total exerted material strain triggering the switching is heavily dependent on NP size and the applied stimulus and that guest-induced switchability can be fully realized in NP@flexMOF hybrid materials. Authors Jan Berger, Stephanie Terruzzi, Hana Bunzen, Filippo Ballerini, Marco Vandone, Marcello Marelli, Luca Braglia, Roland A. Fischer, Valentina Colombo, Gregor Kieslich Journal Small Date 07/01/2025 Consult the paper
Degradation of α-MnO2 in Zn-air battery gas-diffusion electrodes: An investigation based on chemical-state mapping
Abstract Here, we present an integrated ultra-high-vacuum (UHV) apparatus for the growth of complex materials and heterostructures. The specific growth technique is the Pulsed Laser Deposition (PLD) by means of a dual-laser source based on an excimer KrF ultraviolet and solid-state Nd:YAG infra-red lasers. By taking advantage of the two laser sources—both lasers can be independently used within the deposition chambers—a large number of different materials—ranging from oxides to metals, to selenides, and others—can be successfully grown in the form of thin films and heterostructures. All of the samples can be in situ transferred between the deposition chambers and the analysis chambers by using vessels and holders’ manipulators. The apparatus also offers the possibility to transfer samples to remote instrumentation under UHV conditions by means of commercially available UHV-suitcases. The dual-PLD operates for in-house research as well as user facility in combination with the Advanced Photo-electric Effect beamline at the Elettra synchrotron radiation facility in Trieste and allows synchrotron-based photo-emission as well as x-ray absorption experiments on pristine films and heterostructures. Authors Benedetto Bozzini, Alessandro Alleva, Valentina Bonanni, Regina Ciancio, George Kourousias, Francesco Guzzi, Piu Rajak, Alessandra Gianoncelli Journal Electrochimica Acta Date 20/12/2024 Consult the paper
Raman Microscopy Identification of Secondary Spurious Phases in Molten GdSr2RuCu2O8-δ Superconductor for Photonics and Plasmonic Applications
Abstract Plasmonic and Photonics applications of superconducting materials, suggested at first by the necessity to minimize the dissipative losses of conventional metals in the high frequency ranges, are topics of growing interest in Optics. In this perspective, GdSr2RuCu2O8-δ (Gd1212) Rutheno-Cuprate Superconductor presents very promising properties, showing both superconducting and magnetically ordered phases coexisting in the same cell. To investigate its features, the fabrication of macroscopic crystallographically oriented samples is necessary. The use of melt texturing techniques has shown to be among the most effective ways to achieve the best characteristics, although the fabrication of high-quality Gd1212 samples is intrinsically difficult. To reach a better understanding of Gd1212 incongruent melting reaction, a series of bulk samples annealed at temperatures below and above the melting temperature was prepared. Raman Microscopy and Mapping performed on molten and re-solidified samples revealed the presence of different phases, corresponding to those identified in our previous studies. These observations were also confirmed by XRD, TGA-DTA, and SEM+EDS characterisations. Secondary phases formation showed a strong dependence on the temperature of the annealing treatments. Susceptibility and magnetization measurements show both superconducting and magnetic transitions and a contribution of different spurious magnetic phases as suggested by EDS. Authors Marcello Gombos, Stefano Managò, Danilo Zola, Giovanni Carapella, Oreste Tarallo, Vito Mocella, Anna Chiara De Luca, Ivo Rendina, Francesco Ruffo, Pasquale Orgiani, Regina Ciancio Journal Accepted at the Annual Meeting of the Association for Computational Linquistics (ACL), Arxiv preprint: 2402.11655 Date 31/10/2024 Consult the paper
Effects of In-Air Post Deposition Annealing Process on the Oxygen Vacancy Content in Sputtered GDC Thin Films Probed via Operando XAS and Raman Spectroscopy
Abstract We investigate the ionic mobility in room-temperature RF-sputtered gadolinium doped ceria (GDC) thin films grown on industrial solid oxide fuel cell substrates as a function of the air-annealing at 800 and 1000 °C. The combination of X-ray diffraction, X-ray photoelectron spectroscopy, operando X-ray absorption spectroscopy, and Raman spectroscopy allows us to study the different Ce3+/ Ce4+ ratios induced by the post growth annealing procedure, together with the Ce valence changes induced by different gas atmosphere exposure. Our results give evidence of different kinetics as a function of the annealing temperature, with the sample annealed at 800 °C showing marked changes of the Ce oxidation state when exposed to both reducing and oxidizing gas atmospheres at moderate temperature (300 °C), while the Ce valence is weakly affected for the 1000 °C annealed sample. Raman spectra measurements allow us to trace the responses of the investigated samples to different gas atmospheres on the basis of the presence of different Gd–O bond strengths inside the lattice. These findings provide insight into the microscopic origin of the best performances already observed in SOFCs with a sputtered GDC barrier layer annealed at 800 °C and are fundamental to further improve sputtered GDC thin film performance in energy devices. Authors Nunzia Coppola, Sami Ur Rehman, Giovanni Carapella, Luca Braglia, Vincenzo Vaiano, Dario Montinaro, Veronica Granata, Sandeep Kumar Chaluvadi, Pasquale Orgiani, Piero Torelli, Luigi Maritato, Carmela Aruta, Alice Galdi Journal ACS Applied Electronic Materials Date 25/09/2024 Consult the paper
La0.2Sr0.25Ca0.45TiO3 Surface Reactivity with H2: A Combined Operando NEXAFS and Computational Study
Abstract A-site doped SrTiO3 is considered as a promising substitute for traditional anodic metals in solid oxide fuel cells (SOFCs). In this study, we present the reactivity of La0.2Sr0.25Ca0.45TiO3 (LCSTO), La0.2Sr0.7TiO3 (LSTO), and SrTiO3 (STO) toward H2 by operando ambient pressure NEXAFS spectroscopy and theoretical spectra simulation with FDMNES code. The samples were synthesized by MBE (molecular beam epitaxy), hydrothermal, and modified-Pechini routes. We found that the reducibility of the samples depends not only on their stoichiometry but also on the morphology, which is determined by the synthetic method. The results of these experiments give insight into the reducibility of Ti4+ in perovskites as well as the opportunity to further optimize the synthesis of these materials to obtain the best performance for SOFC applications. Authors F. Bassato, S. Mauri, L. Braglia, A. Yu. Petrov, E. Dobovičnik, F. Tavani, A. Tofoni, P. Ferrer, D. Grinter, G. Held, P. D’Angelo, P. Torelli Journal The Journal of Physical Chemistry Letters Date 13/08/2024 Consult the paper
Enhancing Multi-Tip Artifact Detection in STM Images Using Fourier Transform and Vision Transformers
Abstract We address the issue of multi-tip artifacts in Scanning Tunneling Microscopy (STM) images by applying the fast Fourier transform (FFT) as a feature engineering method. We fine-tune various neural network architectures using a synthetic dataset, including Vision Transformers (ViT). The FFT-based preprocessing significantly improves the performance of ViT models compared to using only the grayscale channel. Ablation experiments highlight the optimal conditions for synthetic dataset generation. Unlike traditional methods that are challenging to implement for large datasets and used offline, our method enables on-the-fly classification at scale. Our findings demonstrate the efficacy of combining the Fourier transform with deep learning for enhanced artifact detection in STM images, contributing to more accurate analysis in material science research. Authors Tommaso Rodani, Alessio Ansuini, Alberto Cazzaniga Journal ICML ’24 Workshop ML for Life and Material Science: From Theory to Industry Applications Publication date 17/07/2024 Consult the paper