title: Synergic combination of the sol-gel method with dip coating for plasmonic devices.
abstract: Biosensing technologies based on plasmonic nanostructures have recently attracted significant attention due to their small dimensions, low-cost and high sensitivity but are often limited in terms of affinity, selectivity and stability. Consequently, several methods have been employed to functionalize plasmonic surfaces used for detection in order to increase their stability. Herein, a plasmonic surface was modified through a controlled, silica platform, which enables the improvement of the plasmonic-based sensor functionality. The key processing parameters that allow for the fine-tuning of the silica layer thickness on the plasmonic structure were studied. Control of the silica coating thickness was achieved through a combined approach involving sol-gel and dip-coating techniques. The silica films were characterized using spectroscopic ellipsometry, contact angle measurements, atomic force microscopy and dispersive spectroscopy. The effect of the use of silica layers on the optical properties of the plasmonic structures was evaluated. The obtained results show that the silica coating enables surface protection of the plasmonic structures, preserving their stability for an extended time and inducing a suitable reduction of the regeneration time of the chip.
authors.affiliation: University of Cagliari, Department of Physics, S.P. Monserrato-Sestu Km 0.7, 09042 Monserrato, Italy.
authors.forename: Cristiana
authors.initials: C
authors.lastname: Figus
authors.affiliation: University of Pavia, Department of Physics, Via Agostino Bassi 6, 27100 Pavia, Italy.
authors.forename: Maddalena
authors.initials: M
authors.lastname: Patrini
authors.affiliation: University of Pavia, Department of Physics, Via Agostino Bassi 6, 27100 Pavia, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Floris
authors.affiliation: University of Pavia, Department of Physics, Via Agostino Bassi 6, 27100 Pavia, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Fornasari
authors.affiliation: Plasmore S.r.l., Via Grazia Deledda 4, 21020 Ranco, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Pellacani
authors.affiliation: Plasmore S.r.l., Via Grazia Deledda 4, 21020 Ranco, Italy.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Marchesini
authors.affiliation: Plasmore S.r.l., Via Grazia Deledda 4, 21020 Ranco, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Valsesia
authors.affiliation: University of Cagliari, Department of Physics, S.P. Monserrato-Sestu Km 0.7, 09042 Monserrato, Italy ; University of Cagliari, Department of Chemistry and Geology, S.P. Monserrato-Sestu Km 0.700, 09042 Monserrato, Cagliari, Italy.
authors.forename: Flavia
authors.initials: F
authors.lastname: Artizzu
authors.affiliation: University of Cagliari, Department of Physics, S.P. Monserrato-Sestu Km 0.7, 09042 Monserrato, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Marongiu
authors.affiliation: University of Cagliari, Department of Physics, S.P. Monserrato-Sestu Km 0.7, 09042 Monserrato, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Saba
authors.affiliation: University of Pavia, Department of Physics, Via Agostino Bassi 6, 27100 Pavia, Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Marabelli
authors.affiliation: University of Cagliari, Department of Physics, S.P. Monserrato-Sestu Km 0.7, 09042 Monserrato, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Mura
authors.affiliation: University of Cagliari, Department of Physics, S.P. Monserrato-Sestu Km 0.7, 09042 Monserrato, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Bongiovanni
authors.affiliation: University of Cagliari, Department of Physics, S.P. Monserrato-Sestu Km 0.7, 09042 Monserrato, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Quochi
keywords: biosensors; nanodevices; plasmonics; sol–gel; thin films
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