title: Site-Selective Surface-Enhanced Raman Detection of Proteins.
abstract: Strategies for protein detection via surface-enhanced Raman spectroscopy (SERS) currently exploit the formation of randomly generated hot spots at the interfaces of metal colloidal nanoparticles, which are clustered together by intrusive chemical or physical processes in the presence of the target biomolecule. We propose a different approach based on selective and quantitative gathering of protein molecules at regular hot spots generated on the corners of individual silver nanocubes in aqueous medium at physiological pH. Here, the protein, while keeping its native configuration, experiences an intense local E-field, which boosts SERS efficiency and detection sensitivity. Uncontrolled signal fluctuations caused by variable molecular adsorption to different particle areas or inside clustered nanoparticles are circumvented. Advanced electron microscopy analyses and computational simulations outline a strategy relying on a site-selective mechanism with superior Raman signal enhancement, which offers the perspective of highly controlled and reproducible routine SERS detection of proteins.
authors.affiliation: Institute of Applied Physics "Nello Carrara", National Research Council , via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy.
authors.forename: Paolo
authors.identifier: 0000-0002-8488-5867
authors.initials: P
authors.lastname: Matteini
authors.affiliation: Institute of Applied Physics "Nello Carrara", National Research Council , via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy.
authors.forename: Maximilien
authors.initials: M
authors.lastname: Cottat
authors.affiliation: Department of Chemical and Geological Sciences, University of Modena e Reggio Emilia , via Campi 103, 41125 Modena, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Tavanti
authors.affiliation: Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences , 13 Prospekt Entuziastov, 410049 Saratov, Russia.
authors.forename: Elizaveta
authors.initials: E
authors.lastname: Panfilova
authors.affiliation: Institute for Microelectronics and Microsystems, National Research Council , zona industriale strada VIII n.5, 95121 Catania, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Scuderi
authors.affiliation: Institute for Microelectronics and Microsystems, National Research Council , zona industriale strada VIII n.5, 95121 Catania, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Nicotra
authors.affiliation: Department of Chemical and Geological Sciences, University of Modena e Reggio Emilia , via Campi 103, 41125 Modena, Italy.
authors.forename: Maria Cristina
authors.identifier: 0000-0003-3428-5297
authors.initials: MC
authors.lastname: Menziani
authors.affiliation: Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences , 13 Prospekt Entuziastov, 410049 Saratov, Russia.|Saratov National Research State University , 83 Ulitsa Astrakhanskaya, 410012 Saratov, Russia.
authors.forename: Nikolai
authors.initials: N
authors.lastname: Khlebtsov
authors.affiliation: Institute of Applied Physics "Nello Carrara", National Research Council , via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy.
authors.forename: Marella
authors.initials: M
authors.lastname: de Angelis
authors.affiliation: Institute of Applied Physics "Nello Carrara", National Research Council , via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Pini
mesh_terms: D003102:Colloids / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D053768:Metal Nanoparticles / Q000737:chemistry; D008958:Models, Molecular; D010316:Particle Size; D011506:Proteins / Q000032:analysis*; D011759:Pyrrolidines / Q000737:chemistry; D012834:Silver / Q000737:chemistry; D013059:Spectrum Analysis, Raman; D013499:Surface Properties
chemical_list: D003102:Colloids; D011506:Proteins; D011759:Pyrrolidines; D012834:Silver
keywords: SERS; biomolecules; computational simulations; crystal facets; phosphate buffer; plasmonic nanoparticles; silver nanocubes