title: Triggering and monitoring plasmon-enhanced reactions by optical nanoantennas coupled to photocatalytic beads.
abstract: Plasmonic metal/semiconductor nanocomposites promise to be a breakthrough for boosting and investigating photon-assisted processes at the nanoscale, with exciting perspectives for energy conversion and catalysis. However, the efficiency and selectivity of these surface processes are still far from being controlled. Here, shown for the first time, is a new class of photocatalyst which is based on the synergistic combination of bowtie-like gold nanoantennas and SiO2 /TiO2 core/shell oxide beads. These systems are exploited as efficient near-field optical light concentrators, stimulating photon-driven processes at the metal-semiconductor interface. Extraordinary enhancements of photodegradation rates (minutes instead of hours) result from matching the nanoantenna surface plasmon resonance with the optical absorption of organic dyes and the excitation source wavelength. Moreover, strong Raman enhancements are observed allowing for direct in-situ monitoring of reaction progress of different analytes on the same site.
authors.affiliation: INSTM and Chemistry for Technologies Lab., University of Brescia, via Branze 38, 25123 Brescia, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Salmistraro
authors.forename: Adam
authors.initials: A
authors.lastname: Schwartzberg
authors.forename: Wei
authors.initials: W
authors.lastname: Bao
authors.forename: Laura E
authors.initials: LE
authors.lastname: Depero
authors.forename: Alexander
authors.initials: A
authors.lastname: Weber-Bargioni
authors.forename: Stefano
authors.initials: S
authors.lastname: Cabrini
authors.forename: Ivano
authors.initials: I
authors.lastname: Alessandri
keywords: SERS; core/shell materials; nanoantennas; nanofabrication; photocatalysis