SMILEs
STRUCTURAL MOLECULAR IMAGING LIGHT ENHANCED SPECTROSCOPIES

People

Andrea Giugni

Research Scientists

Introduction

​The field of plasmonics has attracted increasingly the interest of a wide audience over the past two decades, all moved by the disclosure of many fundamental scientific breakthroughs. New ideas and new tools for the investigation have led to fascinating experimental results on physic and biology pushing to a new level of the comprehension of the processes that rule solid state and wild life. 

Since 2014, Andrea has a research Scientist position at Division of Physical Sciences and Engineering of KAUST University where he collaborates to the realization of advanced bio-physic lab. In this contest, he is developing a multi spectroscopy SPM to probe simultaneously chemical, structural and charge transport properties at the nanoscale exploiting synergic phenomena: extreme local field enhancement and quantum confinement of hot plasmonic carriers at nanoscale mediated by a three-dimensional plasmonic nanostructure. This, integrated in an atomic force microscope, allows also the concurrently measure of topography and force spectroscopy at the nanoscale. The underlying phenomena are the conversion of SPPs into photons or hot electrons in metal nanostructures. It realizes an exceptional optical probe breaking the optical limit and generating ideal current source. At such small sizes, < 20nm, confinement produces the brightest nano source and develops a large number of carriers with high energy, completely different from what happens in the plasmonic wave damping process in bulk where excited carriers have very small energies and the scattering photon efficiency is faint. For this reason, the nano probes are the most suitable for injection of plasmonic carriers into semiconductors or into molecules on the surface. We foresee that these techniques will play a key role for relate the functional and structural properties of matter at the nanoscale, and it will open to a deeper understand of phenomena at the basis of hot electron injection plasmonic nano-devices developed in energy harvesting, photo-catalysis, and solar cells research areas.

Research Interests

Sub-diffraction limited Coherent Anti-Stokes Raman scattering from the tip of a plasmonic nanocone

In this paper we demonstrate, for the first time to our knowledge, the possibility to detect the Coherent Anti-Stokes Raman Scattering (CARS) signal from the tip of a plasmonic nanocone with sub-diffraction resolution. Pump and Stokes beam from two intrinsically synchronized 80MHz ps pulsed sources have been converted to radial polarization and coupled to the propagating modes of a metallic nanocone. The two plasmonic waves induced at the surface of the nanocone propagated up to its distal apex while experiencing adiabatic compression of the electromagnetic field. The nonlinear interaction of the two beams at the tip led to the generation of an Anti-Stokes signal that could be collected in far-field with a microscope objective and measured. The emission spectrally shows to be consistent with the expected CARS signal arising from the molecules previously deposited at the tip of the nanocone, hence demonstrating its intrinsically sub-diffraction limit origin. This result paves the way to the development of nonlinear coherent Raman spectroscopy at nanoscale.

 

Controlled deposition of DNA molecules on superhydrophobic surfaces

We report recent results on the control of the deposition of DNA suspended among microfabricated structures that show super-hydrophobic behavior. Regular arrays of cylindrical pillars have been obtained in silicon substrates by means of standard optical lithography techniques, with different size of pillars, reciprocal distance, and periodical arrangement. Structures have been fabricated having either the whole surface coated by a hydrophobic layer or, alternatively, having the top of the pillar made with a hydrophilic material, while the rest of the structure surface was hydrophobically coated. Both surfaces display super-hydrophobicity when a drop of water is deposited on top. The deposition of filaments of DNA suspended between pillars has been analyzed for different structure geometries and surface types as a function of the speed with which the drop of DNA solution was drag on the surface, revealing important information on the way to control the deposition of DNA filaments on these substrates.​

Selected Publications

​P. Benassi, M. Nardone, A. Giugni, G. Baldi, and A. Fontana, “Collective excitations in liquid and glassy 3-methylpentane”, Phys. Rev. B 9/2015; http://dx.doi.org/10.1103/PhysRevB.92.104203

M Lorenzoni, A Giugni, E Di Fabrizio, F Pérez-Murano, A Mescola and B Torre “Nanoscale reduction of graphene oxide thin films and its characterization” Nanotechnology, Volume 26, Number 2 (2015) doi:10.1088/0957-4484/26/28/285301

E. Miele, A. Accardo, A. Falqui, M. Marini, A. Giugni, M. Leoncini, F. De Angelis, R. Krahne, E. Di Fabrizio "Writing and Functionalisation of Suspended DNA Nanowires on Superhydrophobic Pillar Arrays" Small (2015) DOI: 10.1002/smll.201401649

A Giugni, M Allione, B Torre, G Das, M Francardi, M Moretti, M Malerba, G Perozziello, P Candeloro, E Di Fabrizio. “Adiabatic nanofocusing: spectroscopy, transport and imaging investigation of the nano world”. Journal of optics 11/2014; 16(11):114003. DOI:10.1088/2040-8978/16/11/114003

M. Lorenzoni, A Giugni and B Torre “Oxidative and carbonaceous patterning of Si surface in an organic media by scanning probe lithography” Nanoscale Research Letters 2013, 8:75  doi:10.1186/1556-276X-8-75

Education

​2004 Ph.D. degree in Physics - University of L’Aquila, Italy
1999 Laurea Degree in Physics University of Florence, Italy

Professional Profile

​2014-2015 Research Scientist at Division of Physical Sciences and Engineering at KAUST - King Abdullah University of Science and Technology, Kingdom of Saudi Arabia
2011-2013 Post-doctoral position IIT- Istituto Italiano di Tecnologia, Italy
2010 Researcher at INRiM - National Institute of Metrological Research, Italy
2004-2009 Post-doctoral L’Aquila University and Roma University “La Sapienza”, Italy
1999 Scientific collaboration fellow LENS (European Laboratory for Non-linear Spectroscopy), Italy

Scientific and Professional Memberships

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