Congratulations to Stefano Managò, Gianluigi Zito, Alessandra Rogato, Maurizio Casalino, Emanuela Esposito, Anna Chiara De Luca and Edoardo De Tommasi for their last paper on ACS: Applied Materials & Interfaces: "Bio-derived three-dimensional hierarchical nanostructures as efficient SERS substrates for cell membrane probing".
In this work, the use of complex, bio-derived nanostructures as efficient surface-enhanced Raman scattering (SERS) substrates is proposed for the chemical analysis of cellular membranes. These structures were directly obtained from a suitable gold metalization of Pseudonitzchia multistriata diatom silica shell (the so called frustule), whose grating-like geometry provides large light coupling with external radiation, whereas its extruded, sub-wavelength lateral edge provides excellent interaction with cells without steric hindrance. We carried out numerical simulations and experimental characterizations of the supported plasmonic resonances and optical near-field amplification. We thoroughly evaluated the SERS substrate enhancement factor (EF) as a function of the metalization parameters, and finally applied the nanostrucures for discriminating cell membrane Raman signals. In particular, we considered two cases where membrane composition plays a fundamental role in assessment of several pathologies, i.e. red blood cells and B-leukemia REH cells.