Hello, 

my name is Renato Torre and I am a professor at the University of Firenze in Italy; in this site you can find a short summary of my present and past research work, as well as some data and support for the courses I am teaching.

Prof. Renato Torre

European Lab. for Non-Linear Spectroscopy (LENS) and Dpt. of Physics and Astronomy, Univ. of Firenze

Via Carrara 1, 50019 Sesto Fiorentino, Firenze, Italy

Tel: #39-055-4572495; skype: rena.torre

New  "Laurea" in Material Science  

In the upcoming academic year of 2023-2024, the University of Firenze will be launching a new Bachelor's degree program in Material Science, which is known as "Laurea Triennale in Scienza dei Materiali" in Italian. This program will require 3 years of attendance and the completion of a final thesis. 


More information (in Italian)

  

Nell'imminente anno accademico 2023-2024, l'Università di Firenze lancerà un nuovo corso di laurea triennale in Scienza dei Materiali. Questo programma richiederà 3 anni di frequenza e la presentazione di una tesi finale. 



per Approfondire


Research and Highlights

Protein Self-Assembling Dynamics


Amyloidogenic and non-amyloidogenic molten globule conformation of β-lactoglobulin in self-crowded regime

Sara Venturi, B. Rossi, M. Tortora, Renato Torre et al. Inter. J. of Biological Macromolecules 242 (2023) 124621 


Multi-length scale structural investigation of lysozyme self-assembly

S. Catalini, ....,  R. Mezzenga  and Renato Torre. iScience 25 (2022) 104586


Probing Globular Protein Self-Assembling Dynamics by Heterodyne Transient Grating Experiments

S. Catalini, A. Taschin, P. Bartolini, P. Foggi and Renato Torre.  Appl. Sci. 9 (2019) 405

Self-assembling phenomena of biomolecules are characterized by different steps, in which the conformational rearrangements and intermolecular associations drive the formation of stable structures of increasing complexity (e.g. amyloid fibrils, hydrogel networks, ...). Protein-based hydrogels have recently received great attention since they can be the key to develop novel biomaterials. In fact, hydrogels have the capability to retain inside their matrix a great amount of water (up to 97%), which make these materials similar to biological tissues. Protein hydrogels are therefore of great interest in many fields spanning from the medical to the nanotechnological. We undertaken a systematic study of  self-assembling phenomena taking place in biologic samples by means of different spectroscopic investigation, e.g HD-TG, OKE of THz  measurements as a function of the environmental conditions.

Molecular insights on the β-lactoglobulin thermal unfolding and aggregation are derived from FTIR and UV Resonance Raman (UVRR) investigations. We propose an in situ and in real-time approach that thanks to the identification of specific spectroscopic markers can distinguish the two different unfolding pathways pursued by β-lactoglobulin during the conformational transition from the folded to the molten globule state, as triggered by the pH conditions.

Dynamics of Liquid Water: recent experimental investigations

Modification of local and collective dynamics of water in perchlorate

solution, induced by pressure and concentration

C. Calvagna ,  ..., and Renato Torre

Journal of Molecular Liquids 337 (2021) 116273


Pressure Effects on Water Dynamics by Time-Resolved Optical Kerr Effect 

A.Taschin, P. Bartolini, S. Fanetti, A.Lapini, M.Citroni, R.Righini, R.Bini and Renato Torre 

J. Phys. Chem. Lett. 11 (2020) 3063


Vibrational Spectroscopy and Dynamics of Water

Perakis, F.; Marco, L.; Shalit, A.; Tang, F.; Kann, Z. R.; Kuhne, T. D.; Torre, R.; Bonn, M.; Nagata, Y.

Chem Rev 116 (2016), 7590–7607.


Optical Kerr Effect of Liquid and Supercooled Water: The Experimental and Data Analysis Perspective.

A. Taschin, P. Bartolini, R. Eramo, R. Righini, and R. Torre.

Journal of Chemical Physics,141 (2014) 084507.


Evidence of two distinct local structures of water from ambient to supercooled conditions. 

A.Taschin,P. Bartolini, R. Eramo, R. Righini, and R. Torre, 

Nat. Commun. 4 (2013) 1–8 ,

The liquid and supercooled states of water show a series of anomalies whose nature is debated. A key role is attributed to the formation of structural aggregates induced by critical phenomena occurring deep in the supercooled region; the nature of the water anomalies and of the hidden critical processes remains elusive. We used a time-resolved optical Kerr effect investigation of the vibrational dynamics and relaxation processes in supercooled bulk water.

Recently, we presented an overview of time-resolved vibrational spectroscopic studies of liquid water from ambient conditions to the supercooled state. The structure and dynamics of the complex hydrogen-bond network formed by water molecules are discussed, as well as the dissipation mechanism of vibrational energy throughout this network. A broad range of water investigations are addressed:infrared and Raman spectroscopy, femtosecond pump−probe, photon-echo, optical Kerr effect, sum-frequency generation, and two-dimensional infrared spectroscopic studies. By comparison of the complementary aspects probed by various linear and nonlinear spectroscopic techniques, a coherent picture of water dynamics and energetics emerges.



Random Laser and Innovative Radiation Sources

Perspectives and recent advances in super-resolution spectroscopy: Stochastic and disordered-based approaches 

A. Boschetti, L. Pattelli, R. Torre, D.S. Wiersma,

 Applied Physics Letters, 120 (2022) 250502.


Spectral super-resolution spectroscopy using a random laser 

A. Boschetti, A. Taschin, P. Bartolini, A. Kumar Tiwari, L. Pattelli, R. Torre and D. S. Wiersma

Nature Photonics (2019) 


Remote control of liquid crystal elastomer random laser using external stimuli

A-K. Tiwari, L. Pattelli, Renato Torre and D.-S. Wiersma. 

App. Phys. Lett. 113 (2018) 013701

Distinct design for a random laser based on a composite material consisting of an elastomeric liquid crystal with embedded TiO2 nanoparticles. Random lasing action can be controlled by an external, non-contact light stimulus; this induces a rearrangement of the elastomeric liquid crystals which moves the laser body in and out of the focal plane of a pump laser, pushing its emission above or below the lasing threshold.

Transport phenomena at the nanoscale investigated by pulsed x-ray

Hard X-ray transient grating spectroscopy on bismuth germanate

Jérémy R. Rouxel et al.

Nature Photonics, 15 (2021) 499-503.

To date, the modeling and understanding of transport phenomena at the nanoscale remains an open problem in materials science. Physical modeling fails to describe some of the most relevant transport phenomena when they are characterized by nanometric wavelengths, e.g. the propagation of very high frequency acoustic or phonon modes in the THz band, or thermal propagation on the nanoscale. Furthermore, the miniaturization of devices reached the nanoscale demanding an operational understanding of the different transport processes at this length scale.

The poor understanding of these phenomena is strongly due to the lack of experimental investigations capable of probing the transport processes on such a reduced length scale. This requires the use of short wavelength radiation, and in particular X-rays. The main challenge is to control multiple X-ray beams to generate a coherent interaction with matter at the nanoscale, in order to perform spectroscopy. non-linear X-ray.

Time-domain THz spectroscopy

..... new THz set-up 


THz time-domain spectroscopic investigations of thin films.Taschin, A.; Bartolini, P.; Tasseva, J.; Torre, R. Measurement, 118 (2018), 282-288

- Bone investigations

New investigation techniques are constantly required to better characterize bone ultrastructure, we provide an extended investigation of the vibrational features of bone tissue in the 0.1-3 THz frequency range by time-domain THz spectroscopy supported by a combination of X-ray diffraction and DFT-normal modes calculations. In particular, we investigate the effect of heating on bone tissue and synthetic calcium-phosphates compounds with close structure and composition to bone mineral. We thus demonstrate that the narrow vibrational mode at 2.1 THz in bone samples exposed to thermal treatment from a lattice mode of stoichiometric hydroxyapatite. The THz spectral range therefore provides a clear signature of the crystalline state of the investigated bone tissue and could, therefore be used to monitor or identify structural transitions occurring in bone upon heating.


Time-domain THz spect. of the characteristics of hydroxyapatite provides a signature of heating in bone tissue. 

Plazanet M, Tasseva J, Bartolini P, Taschin A, Torre R, Combes C, et al. 

PLoS ONE 13 (2018) e0201745.


- Artwork investigations

THz pulse imaging and spectroscopy is an emerging non-invasive method for the characterization of cultural heritage artefacts that provides complementary information to traditional analytical tools.We explored artworks drawing materials with THz-Time Domain Spectroscopy (THz-TDS) extending the investigation to thin layers of inks, that was never realized previously. We developed a new speci.c experimental method and data analysis to disentangle the multiple reflection signals. Thanks to a high signal to noise ratio and the accurate analysis implemented, our measurements enable the calculation of the absolute absorption coefficient and index of refraction of the materials, as well as the sample thickness down to tens of microns both in single layer and bilayer configurations.


Drawing materials studied by THz spectroscopy.

A. Taschin; P.Bartolini; J. Tasseva; J. Striova; R. Fontana; C. Riminesi; Renato Torre.

Acta Imeko, 6 (2017) 12-17


Thin layered drawing media probed by THz time-domain spectroscopy

J. Tasseva, A. Taschin, P. Bartolini, J. Striova, R. Fontana, R. Torre

Analyst 142 (2017) 42-47


- High-Precision Terahertz Spectroscopy


Frequency-Comb-Assisted Terahertz Quantum Cascade Laser Spectroscopy

S. Bartalini, L. Consolino, P. Cancio, P. De Natale, P. Bartolini, A. Taschin, M. De Pas, H. Beere, D. Ritchie, M. S. Vitiello, and R. Torre

Phys. Rev. X 4, 021006 (2014)

Potential Qubits,  Phonons and Spin Dynamics

The investigation of the magnetization dynamics of a vanadyl complex in both solid-state and frozen solution, showed an anomalous and unprecedentedly observed field dependence of the relaxation time. The temperature dependence of the weight of the processes was found to well correlate with the low energy vibrations as determined by THz spectroscopy. This detailed experimental comparative study represents a fundamental step to understand the spin dynamics of potential molecular quantum bits, and enriches the guidelines to design molecule-based systems with enhanced quantum coherence.

First-Principles Investigation of Spin−Phonon Coupling in Vanadium-Based Molecular Spin Quantum Bits

A.Albino, S. Benci, L. Tesi, M. Atzori, Renato Torre, S. Sanvito, R. Sessoli, and A. Lunghi

Inorg. Chem. 2019, 58, 10260−10268


Spin Dynamics and Phonons, Insights into Potential Molecular Qubits

S. Benci, L. Tesi, M. Atzori, R. Sessoli and Renato Torre

Proceedings 2019, 26, 46;


Structural Effects on the Spin Dynamics of Potential Molecular Qubits 

M. Atzori, S. Benci, E.Morra,   L. Tesi, M.Chiesa,  Renato Torre, L. Sorace, and R. Sessoli

Inorg. Chem. 57 (2018) 731−740


Structural Effects on the Spin Dynamics of Potential Molecular Qubits 

M. Atzori, S. Benci, E.Morra,   L. Tesi, M.Chiesa,  Renato Torre, L. Sorace, and R. Sessoli

Inorg. Chem. 57 (2018) 731−740


Scaling Up Electronic Spin Qubits into a Three-Dimensional Metal−Organic Framework

T. Yamabayashi, M. Atzori, L.Tesi, G. Cosquer, F. Santanni,  M.-E. Boulon, E. Morra, S. Benci, Renato Torre, M. Chiesa,  L. Sorace, R. Sessoli, and M. Yamashita


J. Am. Chem. Soc. 140 (2018) 12090

Spin Dynamics and Low Energy Vibrations: Insights from Vanadyl-Based Potential Molecular Qubits

M. Atzori, L. Tesi, S. Benci, A. Lunghi, R. Righini, A. Taschin, Renato Torre, L. Sorace, and R. Sessoli

Nanoconfined Water

We investigate the vibrational dynamics and the structural relaxation of water nanoconfined in Vycor porous silica samples (pore size 4 nm) at different levels of hydration and temperatures. At low level of hydration, corresponding to two complete superficial water layers, no freezing occurs and water remains mobile at all the investigated temperatures with dynamic features similar, but not equal, to the bulk water. The fully hydrated sample shows formation of ice at about 248 K, this processes does not involve all the contained water; a part of it remains in a supercooled phase. The spectra are obtained as the Fourier transforms of time-resolved heterodyne detected optical Kerr effect (HD-OKE) measurements. The comparison of these spectra with that of bulk water enables us to separately extract and analyze the spectral contributions of the first and second hydration layers, as well as that of bulk-like inner water. We conclude that the extra water entering the pores above ≈ 10 % water/silica weight ratio behaves very similarly to bulk water. At lower levels of hydration, corresponding to two complete superficial water layers or less, the H-bond bending and stretching bands, characteristic of the tetrahedral coordination of water in the bulk phase, progressively disappear: clearly in these conditions the H-bond connectivity is very different from that of liquid water. THz Dynamics of Nanoconfined Water by Ultrafast Optical Spectroscopy, Taschin A., Bartolini P. and Torre R. Meas. Sci. Technol. 28 (2017) 014009,Confinement, entropic effects and hydrogen bond network fluctuations of water in Nafion membrane Plazanet, M., Torre, R., Sacchetti, F.

J. of Molecular Liquids, 219 (2016) Pages 1161–1164.

Supercooling and Freezing Processes in Nanoconfined Water by Time-Resolved Optical Kerr Effect Spectroscopy

A.Taschin, P. Bartolini, A. Marcelli, R. Righini, and R. Torre.

Journal of Physics: Condensed Matter, 27 (2015) 194107.

A comparative study on bulk and nanoconfined water by time-resolved optical Kerr effect spectroscopy

A. Taschin, P. Bartolini, A. Marcelli, R. Righini, & R. Torre.

Faraday Discussion 167 (2013) 293

Cryotechniques

In this study, a novel cryopreservation technique based on a rapid cooling procedure was applied to adults of C. elegans, a complex metazoan organism, the nematodes survive to a rapid cooling and storage in liquid nitrogen (−196 °C) with a very high survival percentage (85%). The procedure relies on low cryoprotectant percentage and ultra rapid cooling technique. The high cooling rate is achieved through the reduction of sample volumes and the effectiveness of a nylon carrier. Our technique complies with the requirements for vitrification. Our results show that this cryopreservation method is valid for both unicellular and multicellular organisms; it is suitable for short or long time storage in liquid-nitrogen. This technique promises to be a unique and simpler method for cryostorage of cells, organisms and tissues.


A non-traditional approach to cryopreservation by ultra-rapid cooling for human mesenchymal stem cells

T. Irdani, B. Mazzanti, L. Ballerini, R. Saccardi, Renato Torre.

PLoS ONE (2019) 14, e0220055.


An ultra-rapid cryo-technique for complex organisms

Irdani, T.; Fortunato, A.; Torre, R.

Cryobiology 71 (2015) 391-397