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Updated: Apr 25, 2026

Author Spotlight: Non-Invasive Imaging of Complex Bio-Structures Using Polarization-Sensitive Two-Photon Microscopy
Published on: September 8, 2023
Linear and circular dichroism in porphyrin J-aggregates probed by polarization modulated scanning near-field optical
Francesco Tantussi1, Francesco Fuso, Maria Allegrini
1Dipartimento di Fisica "Enrico Fermi" and CNISM, Università di Pisa, Istituto Nazionale di Ottica INO-CNR, Sezione di Pisa, Largo Bruno Pontecorvo 3, I-56127 Pisa, Italy.
Abstract:
Polarization modulated scanning near-field optical microscopy (PM-SNOM) is effective in detecting circular and linear dichroism with sub-wavelength resolution. PM-SNOM investigation of the chiroptical properties of single ribbon-like nanosized J-aggregates formed by acid induced aggregation of tris-(4-sulfonatophenyl)phenylporphyrin is reported. Linear dichroism maps give evidence of well-organized chromophores packed in linear arrays within the structure of the nanoribbons. Circular dichroism maps indicate that the molecules forming the nanoribbon have an inherently chiral structure at the local scale.
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