title: Silver colloids as plasmonic substrates for direct label-free surface-enhanced Raman scattering analysis of DNA.
abstract: Ultrasensitive direct SERS analysis offers a powerful analytical tool for the structural characterization and classification of nucleic acids. However, acquisition of reliable spectral fingerprints of such complex biomolecules poses important challenges. In recent years, many efforts have been devoted to overcome these limitations, mainly implementing silver colloids as plasmonic substrates. However, a reliable cross-comparison of results reported in the recent literature is extremely hard to achieve, mostly due to the broad set of different surface properties of the plasmonic nanoparticles. Herein, we perform a thorough investigation of the role played by the metal/liquid interface composition of silver colloids in the direct label-free SERS analysis of DNA. Target molecules of increasing complexity, from short homopolymeric strands to long genomic duplexes, were used as probes. We demonstrate how apparently subtle changes in the colloidal surface chemistry can dramatically modify the affinity and the final SERS spectral profile of DNA. This has significant implications for the future design of new analytical strategies for the detection of DNA using SERS without labels.
authors.affiliation: Medcom Advance, Viladecans Business Park, Edificio Brasil, Bertran i Musitu 83-85, 08840 Viladecans, Barcelona, Spain. luca.guerrini@ctqc.org and Centro Tecnológico de la Química de Catalunya, Carrer de Marcellí Domingo s/n, 43007 Tarragona, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Torres-Nuñez
authors.affiliation: Department of Pure and Applied Chemistry, Technology and Innovation Centre, University of Strathclyde, 99 George Street, Glasgow G1 1RD, UK.
authors.forename: K
authors.initials: K
authors.lastname: Faulds
authors.affiliation: Department of Pure and Applied Chemistry, Technology and Innovation Centre, University of Strathclyde, 99 George Street, Glasgow G1 1RD, UK.
authors.forename: D
authors.initials: D
authors.lastname: Graham
authors.affiliation: Medcom Advance, Viladecans Business Park, Edificio Brasil, Bertran i Musitu 83-85, 08840 Viladecans, Barcelona, Spain. luca.guerrini@ctqc.org and Centro Tecnológico de la Química de Catalunya, Carrer de Marcellí Domingo s/n, 43007 Tarragona, Spain and ICREA, Passeig Lluís Companys 23, 08010 Barcelona, Spain. ramon.alvarez@urv.cat.
authors.forename: R A
authors.initials: RA
authors.lastname: Alvarez-Puebla
authors.affiliation: Medcom Advance, Viladecans Business Park, Edificio Brasil, Bertran i Musitu 83-85, 08840 Viladecans, Barcelona, Spain. luca.guerrini@ctqc.org and Department of Pure and Applied Chemistry, Technology and Innovation Centre, University of Strathclyde, 99 George Street, Glasgow G1 1RD, UK.
authors.forename: L
authors.initials: L
authors.lastname: Guerrini
mesh_terms: D003102:Colloids; D004247:DNA / Q000032:analysis*; D053768:Metal Nanoparticles; D012834:Silver; D013059:Spectrum Analysis, Raman
chemical_list: D003102:Colloids; C586932:colloidal silver; D012834:Silver; D004247:DNA