title: Improving the Selective Efficiency of Graphene-Mediated Enhanced Raman Scattering through Molecular Imprinting.
abstract: Enhancement of Raman scattering signal through graphene is an important property that could be exploited for producing innovative sensing devices with advanced properties. Because the enhancement of Raman scattering is due to only a chemical mechanism, the amplification of the signal is lower than that one produced by excitation of localized surface plasmons. The combination of a highly selective technique, which is molecular imprinting, with graphene-mediated enhanced Raman scattering, represents a new synergistic approach that we have developed in the present work. The careful material design has allowed obtaining a porous composite embedding exfoliated graphene and molecular cavities specifically designed for recognizing Rhodamine 6G. The molecularly imprinted porous samples have shown a signal enhancement that increases as a function of the number of molecular cavities, which are also accountable for the molecular recognition properties. Environmental ellipsometric porosimetry has shown no substantial difference between molecularly imprinted and not-imprinted films confirming that the signal enhancement of the imprinted samples is due to the molecular cavities. Interestingly, the most efficient sample has shown a Raman enhancement per cavity that exceeds the value of 1 × 1012and a remarkable molecular selectivity allowing for a Rhodamine 6G signal amplification 4.5 higher than structural analogues such as Rhodamine B and methylene blue. The robust and flexible matrix ensures a good recyclability of the samples without lack of linear response. These results prove the great potential of molecular imprinting as a general strategy to provide selectivity to GERS-active substrates for a new generation of sensing devices.
authors.affiliation: Laboratorio di Scienza dei Materiali e Nanotecnologie, Dipartimento di Architettura, Design e Urbanistica (DADU), Università di Sassari, CR-INSTM , Palazzo Pou Salit, Piazza Duomo 6, 07041 Alghero (Sassari), Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Carboni
authors.affiliation: Laboratorio di Scienza dei Materiali e Nanotecnologie, Dipartimento di Architettura, Design e Urbanistica (DADU), Università di Sassari, CR-INSTM , Palazzo Pou Salit, Piazza Duomo 6, 07041 Alghero (Sassari), Italy.
authors.forename: Yu
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Laboratoire de Chimie de la Matière Condensée de Paris, UMR 7574, C ollège de France, CNRS, UPMC Univ. Paris 06, Sorbonne Universités , F-75005 Paris, France.
authors.forename: Marco
authors.initials: M
authors.lastname: Faustini
authors.affiliation: Laboratorio di Scienza dei Materiali e Nanotecnologie, Dipartimento di Architettura, Design e Urbanistica (DADU), Università di Sassari, CR-INSTM , Palazzo Pou Salit, Piazza Duomo 6, 07041 Alghero (Sassari), Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Malfatti
authors.affiliation: Laboratorio di Scienza dei Materiali e Nanotecnologie, Dipartimento di Architettura, Design e Urbanistica (DADU), Università di Sassari, CR-INSTM , Palazzo Pou Salit, Piazza Duomo 6, 07041 Alghero (Sassari), Italy.
authors.forename: Plinio
authors.initials: P
authors.lastname: Innocenzi
keywords: exfoliated graphene; graphene-mediated enhanced Raman scattering (GERS); hybrid organic−inorganic; mesoporous films; molecular imprinting; self-assembly; sensing