Photonic properties of nanostructured biomaterials
Applied Photonics & Optoelectronics Nanophotonics and Plasmonics Research

Photonic properties of nanostructured biomaterials

Descrizione dell’attività di ricerca:

Several organisms including algae, flora, insects, and birds, are provided with sub-micrometric structures able to manipulate light with high efficiency, mainly for intra- and inter-species communication. Some of these periodic or quasi-periodic structures can cause coherent or incoherent scattering; others act as one-dimensional, spectrally selective multilayer reflectors, polarization-selective reflectors, two-dimensional diffraction gratings, and photonic crystals, and can be shaped in complex hierarchical architectures whose optical properties rely on a fine interplay between order and disorder. In particular, we study the photonic properties of diatoms, unicellular microalgae which represent the main component of phytoplankton. Their protoplasm is enclosed in a regularly micro- and nano-patterned silica shell, the frustule, which presents some analogies with artificial photonic crystals. We observed several properties (e.g. diffractive-induced light confinement, photoluminescence, manipulation of polarization, UV-R screening) and exploited them in the realization of bio-based super-lensing, bio-derived SERS substrates, optical biosensors, and dielectric metasurfaces, to name a few. These studies are conducted by means of high-performance numerical simulations, transmission and fluorescence imaging, digital holography, photoluminescence spectroscopy, and interaction with structured light. Optical characterization has been recently extended also to living organisms.

Personale coinvolto:

E. De Tommasi | M.A. Ferrara | L. De Stefano | I. Rea

Collaborazioni Nazionali ed Internazionali:

Collaborazioni Nazionali ed Internazionali:

Attrezzature/strumentazioni:

  • DELL workstation (Xeon bi-processor with 2-14 cores, 512 GB RAM, graphic board NVIDIA QUADRO K6000) for numerical simulations.
  • Field Emission Scanning Electron Microscope (Carl Zeiss NTS GmbH 1500 Raith) and Atomic Force Microscope (XE-70 Park’s) for morphological characterization of diatom frustules.
  • Laser sources at 406 nm (diode laser, Micro Laser Systems, L4-408-48B-TE), 532 nm (diode laser, Laserslt, DPSS), and 633 nm (He-Ne laser, Research Electro-Optics, HRP350-EC) for transmission characterization of diatom valves.
  • UV-VIS fiber lamp (Hamamatsu, L10290) for optical characterization of diatom frustules with non-coherent light.
  • UV optics and sensors for the study of the interaction of diatom frustules with UV-R.
  • He-Cd laser source (Kimmon, IK5751I-G) plus spectrometer (Princeton Instruments, SpectraPro 300i) for photoluminescence characterization.
  • Fluorescence microscope (Leica Microsystems, DM6M).
  • Home-made digital holographic microscope (laser source at 660 nm).
  • Liquid-crystal-on-silicon spatial light modulator (Hamamatsu, LCOS-SLM X13138) for the study of the interaction of diatom valves with structured light.

Progetti e contratti attivi:

  • “Photonic properties of diatom frustules – functional meaning and beyond”, Swedish Research Council, grant number 2018-04289, in collaboration with University of Gothenburg (Sweden) and Università della Campania “Luigi Vanvitelli” (Italy). Principal investigator: Prof. Angela Wulff (University of Gothenburg, Sweden).

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