The research activity of our group is focused on two main general topics:
- Materials for advanced diagnostics (e.g. Surface Enhanced Raman Scattering)
- Materials for environment: energy conversion and pollutant removal
Part of our research activity is focused on developing new routes for the synthesis of nanostructured materials. In particular, we are active in the synthesis of plasmonic nanoparticles and nanostructures, hierarchically organized multi‐scale architectures and hybrid metal/polymer or metal/oxide systems.
Our materials are obtained by combining: Colloidal Synthesis Routes, Sol-Gel Methods and Atomic Layer Deposition.
Great attention is focused on the sustainability of synthesis protocols, reducing the environmental impact of the involved reactants and employing wastes (in particular, organic waste) as starting materials.
What follows is a brief description of our recent research:
T-rex and related all-dielectric systems:
Ivano Alessandri, Luca Carletti, Matteo Ferroni, Costantino De Angelis, Irene Vassalini, Bioinspired self-similar all-dielectric antennas: probing the effect of secondary scattering centres by Raman spectroscopy, Materials Advances (2020), 1, 2443-2449, DOI: 10.1039/D0MA00509F
Irene Vassalini, Orhan Sisman, Elisabetta Comini, Ivano Alessandri, The role of morphology in all-dielectric SERS: A comparison between conformal (T-rex) and non-conformal TiO2 shells, Vibrational Spectroscopy (2020), 109,103085, DOI: 10.1016/j.vibspec.2020.103085
N. Bontempi, I. Vassalini, S. Danesi, M. Ferroni, M. Donarelli, P. Colombi, I. Alessandri, Non-plasmonic SERS with silicon: is it really safe? New insights into the optothermal properties of core/shell microbeads, J. Phys. Chem. Lett. (2018), 9, 2127-2132
N. Bontempi, I. Vassalini, I. Alessandri, All-dielectric core/shell resonators: From plasmon-free SERS to multimodal analysis, J. Raman Spectrosc. (2018), 49, 943-953
N. Bontempi, I. Vassalini, S. Danesi, I. Alessandri, ZORRO: zirconium oxide resonators for all-in-one Raman and whispering-gallery-mode optical sensing, Chemical Communications (2017), 10.1039/C7CC06357A
N. Bontempi, E. Biavardi, D. Bordiga, G. Candiani, I. Alessandri*,P. Bergese*, E. Dalcanale*, Probing lysine mono-methylation in histone H3 tail peptides with an abiotic receptor coupled to non-plasmonic resonator, Nanoscale (2017), 9, 8639-8646
N. Bontempi, K. E. Chong, H. W. Orton, I. Staude, D.-Y. Choi, I. Alessandri, Y. S. Kivshar, D. N. Neshev, Highly sensitive biosensors based on all-dielectric nanoresonators, Nanoscale (2017), 9, 4972-4980, doi: 10.1039/C6NR07904K
I. Alessandri, J. R. Lombardi, Enhanced Raman Scattering with Dielectrics, Chemical Reviews (2016), doi: 10.1021/acs.chemrev.6b00365
I. Alessandri, I. Vassalini, M. Bertuzzi, N. Bontempi, M. Memo, A. Gianoncelli, "Ramassays": synergistic enhancement of plasmon-free Raman scattering and mass spectrometry for multimodal analysis of small molecules, Scientific Reports (2016), 6, Article number:34521, doi: 10.1038/srep34521
N. Bontempi, L. Carletti, C. De Angelis, I. Alessandri, Plasmon-free SERS detection of environmental CO2 on TiO2 surfaces, Nanoscale (2016), DOI: 10.1039/c5nr08380j
I. Alessandri, E. Biavardi, A. Gianoncelli, P. Bergese, E. Dalcanale, Cavitands Endow All-Dielectric Beads With Selectivity for Plasmon-Free Enhanced Raman Detection of Nε-Methylated Lysine, ACS-Applied Materials & Interfaces (2015), in press, DOI: 10.1021/acsami.5b08190
N. Bontempi, M. Salmistraro, M. Ferroni, L. E. Depero, I. Alessandri, Probing the spatial extension of light trapping-induced enhanced Raman scattering in high-density Si nanowire arrays, Nanotechnology (2014) 25, 465705.
Plasmonic SERS-active substrates
Irene Vassalini, Nicolò Bontempi, Stefania Federici, Matteo Ferroni, Alessandra Gianoncelli, Ivano Alessandri, Cyclodextrins enable indirect ultrasensitive Raman detection of polychlorinated biphenyls captured by plasmonic bubbles, Chemical Physics Letters (2021), 775, 138674, DOI:10.1016/j.cplett.2021.138674
I. Vassalini, E. Rotunno, L. Lazzarini, I. Alessandri, “Stainless” gold nanorods: preserving shape, optical properties and SERS activity in oxidative environment, ACS-Applied Materials & Interfaces (2015), 7, 18794-18802.
G. Sinha, L.E. Depero, I. Alessandri, Recyclable SERS substrates based on Au- coated nanorods, ACS-Applied Materials and Interfaces (2011), 3(7), 2557-2563.
S. Pal, L. E. Depero, I. Alessandri, Using aggregates of gold nanorods in SER(R)S experiments: an empirical evaluation of some critical aspects, Nanotechnology (2010), 21, 42570.
Finding new strategies for environmental monitoring and remediation, portable and locally applicable in places of interest, is essential to respond to the pressing demand for clean water and soil. At the same time, it is necessary that the new solutions are based on simple materials and techniques, they have low cost and they are characterized by low environmental impact.
Hydrogels and natural polymers extraction:
Irene Vassalini, Giovanni Ribaudo, Alessandra Gianoncelli, Maria Francesca Casula, Ivano Alessandri, Plasmonic hydrogels for capture, detection and removal of organic pollutants, Environmental Science: Nano (2020), 7, 3888-3900, DOI: 10.1039/D0EN00990C.
Laura Benassi, Ivano Alessandri, Irene Vassalini, Assessing Green Methods for Pectin Extraction from Waste Orange Peels, Molecules (2021), 26 (5), 1766;D OI:10.3390/molecules26061766
Marina Maddaloni, Irene Vassalini, Ivano Alessandri, Green Routes for the Development of Chitin/Chitosan Sustainable Hydrogels, Sustainable Chemistry (2020), 1, 325-344.
Other systems for pollutant removals:
Irene Vassalini, Marharyta Litvinava, Ivano Alessandri, All Food Waste-Based Membranes for Chromium(VI) Removal, Environmental Sustainability (2021), 4(2), 429-435, DOI:10.1007/s42398-020-00132-y
Irene Vassalini, Joana Gjipalaj, Stefano Crespi, Alessandra Gianoncelli, Mariella Mella, Matteo Ferroni, Ivano Alessandri, Alginate‐Derived Active Blend Enhances Adsorption and Photocatalytic Removal of Organic Pollutants in Water, Advanced Sustainable Systems (2020), DOI: 10.1002/adsu.201900112
S. Mura, Y. Jiang, I. Vassalini, A. Gianoncelli, I. Alessandri, G. Granozzi, L. Calvillo, N. Senes, S. Enzo, P. Innocenzi, L. Malfatti, Graphene Oxide/Iron Oxide Nanocomposites for Water Remediation. ACS Applied Nano Materials (2018), DOI: 10.1021/acsanm.8b01540
Gjipalaj, I. Alessandri, Easy recovery, mechanical stability, enhanced adsorption capacity and recyclability of alginate-based TiO2 macrobead photocatalysts for water, Journal of Environmental Chemical Engineering 5 (2) (2017), 1763-1770, doi: 10.1016/j.jece.2017.03.017
Smart materials, i.e. materials that can change their structural and/or functional properties in response to external stimuli, (light, pH, electrical and magnetic fields, mechanical stress, corrosion, etc.) are attracting ever growing interests in several key sectors of materials science. Adaptive interfaces, bioinspired actuators, self-healing polymer coatings nanoparticles and tissues are only a few of the most intensively investigated systems.
More recently, we have successfully exploited oscillating chemical reactions to store temporary graphical information in cellulose-based supports, with precise temporal and spatial control. In this way, it has been possible to develop a sort of smart paper.
We have also developed “the phactalyst”, a bimorph photo-actuator (obtained by combining polycarbonate membranes with Carbone Nanotubes and TiO2 NPs) which can be activated by means of common table lamps and can be used for chemical applications, such as the remote and safe triggering of chemical reaction, or as optical shutter for the control of the occurrence of photo-chemical reactions, according to the wavelength of the illuminating light.
Now, we are investigating the possibility to introduce “smartness” and “stimuli-responsivity” to systems generally characterized by a lower degree of dynamicity, such as photonics, energy production and catalysis.
Irene Vassalini, Ivano Alessandri, Domenico de Ceglia, Stimuli-Responsive Phase Change Materials: Optical and Optoelectronic Applications, Materials (2021), 14(12), 3396, DOI: 10.3390/ma14123396
I. Vassalini, I. Alessandri, Switchable Stimuli-Responsive Heterogeneous Catalysis, Catalysts (2018), 8(12), 569; doi:10.3390/catal8120569
I. Vassalini, I. Alessandri, “The phactalysts”: carbon nanotube/TiO2 composites as phototropic actuators for wireless remote triggering of chemical reactions and catalysis, Nanoscale (2017),9, 11446-11451
Ivano Alessandri, Irene Vassalini, System Chemistry in Catalysis: Facing the Next Challenges in Production of Energy Vectors and Environmental Remediation, Catalysts, 11(1), 64; DOI: 10.3390/catal11010064
Pitchiah Esakki Karthik, Ivano Alessandri, Anantharaj Sengeni, A review on electrodes used in electroorganic synthesis and the significance of coupled electrocatalytic reactions, Journal of the Electrochemical Society, 167, 125503
I. Vassalini, I. Alessandri, Switchable Stimuli-Responsive Heterogeneous Catalysis, Catalysts, 8(12), 569; doi:10.3390/catal8120569 (open access)
I. Vassalini, L. Borgese, M. Mariz, S. Polizzi, G. Aquilanti, P. Ghigna, A. Sartorel, V. Amendola, I. Alessandri, Enhanced electrocatalytic oxygen evolution in Au-Fe nanoalloys, Angewandte Chemie International Edition, 2017, doi: 10.1002/anie.201703387
These systems allow for either broadband or selective, efficient light harvesting in the Vis-NIR range. Light is concentrated within nanogap regions, generating intense locale electromagnetic fields, that can assist surface reactions in several ways. We demonstrated that the photo-degradation of different organic pollutants can be controlled with unprecedented spatial and time resolution and the reaction rate can be remarkably enhanced.
M. Salmistraro, A. Schwartzberg, W. Bao, L. E. Depero, A. Weber-Bargioni, S. Cabrini, I. Alessandri, Triggering and monitoring plasmon enhanced reactions by optical nanoantennas coupled to photocatalytic beads, Small (2013) 9, 3301-3307
M. Salmistraro, S. Sassolini, A. Weber-Bargioni, S. Cabrini, I. Alessandri, Fabrication of gold nanoantennas on SiO2/TiO2 core/shell beads to study photon-driven surface reactions, Microelectronic Engineering (2015) 143, 69-73
I. Alessandri, M. Ferroni, L. E. Depero, Plasmon-assisted, spatially resolved laser generation of transition metal oxides from liquid precursors, Journal of Physical Chemistry C (2011) 115, 5174.
I. Alessandri, Plasmonic heating assisted deposition of bare Au nanoparticles on titania nanoshells, Journal of Colloid and Interface Science (2010) 351, 576.
I. Alessandri, L. E. Depero, Using plasmonic heating of gold nanoparticles to generate local SER(R)S-active TiO2 spots, Chemical Communications (2009), 17, 2359.
I. Alessandri, M. Ferroni, L. E. Depero, In situ plasmon heating-induced generation of Au/TiO2 “hot spots” on colloidal crystals, ChemPhysChem, (2009), 10, 1017.
I. Alessandri, M. Ferroni, Exploiting optothermal conversion for nanofabrication: site-selective generation of Au/TiO2 inverse opals, Journal of Materials Chemistry (2009), 19, 7990.
I. Alessandri, L. E. Depero, Laser-induced modification of polymeric beads coated with gold nanoparticles, Nanotechnology (2008) 19, 305301.