title: Pushing back the limits of Raman imaging by coupling super-resolution and chemometrics for aerosols characterization.
abstract: The increasing interest in nanoscience in many research fields like physics, chemistry, and biology, including the environmental fate of the produced nano-objects, requires instrumental improvements to address the sub-micrometric analysis challenges. The originality of our approach is to use both the super-resolution concept and multivariate curve resolution (MCR-ALS) algorithm in confocal Raman imaging to surmount its instrumental limits and to characterize chemical components of atmospheric aerosols at the level of the individual particles. We demonstrate the possibility to go beyond the diffraction limit with this algorithmic approach. Indeed, the spatial resolution is improved by 65% to achieve 200 nm for the considered far-field spectrophotometer. A multivariate curve resolution method is then coupled with super-resolution in order to explore the heterogeneous structure of submicron particles for describing physical and chemical processes that may occur in the atmosphere. The proposed methodology provides new tools for sub-micron characterization of heterogeneous samples using far-field (i.e. conventional) Raman imaging spectrometer.
authors.affiliation: LASIR CNRS UMR 8516, Université Lille 1, Sciences et Technologies, 59655 Villeneuve d'Ascq Cedex, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Offroy
authors.affiliation: LASIR CNRS UMR 8516, Université Lille 1, Sciences et Technologies, 59655 Villeneuve d'Ascq Cedex, France.
authors.forename: Myriam
authors.initials: M
authors.lastname: Moreau
authors.affiliation: LASIR CNRS UMR 8516, Université Lille 1, Sciences et Technologies, 59655 Villeneuve d'Ascq Cedex, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Sobanska
authors.affiliation: Department of Electrical Engineering, University of California at Santa Cruz, Santa Cruz, CA 95064 USA.
authors.forename: Peyman
authors.initials: P
authors.lastname: Milanfar
authors.affiliation: LASIR CNRS UMR 8516, Université Lille 1, Sciences et Technologies, 59655 Villeneuve d'Ascq Cedex, France.
authors.forename: Ludovic
authors.initials: L
authors.lastname: Duponchel