title: Bioinspired systems for metal-ion sensing: new emissive peptide probes based on benzo[d]oxazole derivatives and their gold and silica nanoparticles.
abstract: Seven new bioinspired chemosensors (2-4 and 7-10) based on fluorescent peptides were synthesized and characterized by elemental analysis, (1)H and (13)C NMR, melting point, matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF-MS), and IR and UV-vis absorption and emission spectroscopy. The interaction with transition- and post-transition-metal ions (Cu(2+), Ni(2+), Ag(+), Zn(2+), Cd(2+), Hg(2+), Pb(2+), and Fe(3+)) has been explored by absorption and fluorescence emission spectroscopy and MALDI-TOF-MS. The reported fluorescent peptide systems, introducing biological molecules in the skeleton of the probes, enhance their sensitivity and confer them strong potential for applications in biological fields. Gold and silica nanoparticles functionalized with these peptides were also obtained. All nanoparticles were characterized by dynamic light scattering, transmission electron microscopy, and UV-vis absorption and fluorescence spectroscopy. Stable gold nanoparticles (diameter 2-10 nm) bearing ligands 1 and 4 were obtained by common reductive synthesis. Commercial silica nanoparticles were decorated at their surface using compounds 8-10, linked through a silane spacer. The same chemosensors were also taken into aqueous solutions through their dispersion in the outer layer of silica core/poly(ethylene glycol) shell nanoparticles. In both cases, these complex nanoarchitectures behaved as new sensitive materials for Ag(+) and Hg(2+) in water. The possibility of using these species in this solvent is particularly valuable because the impact on human health of heavy- and transition-metal-ion pollution is very severe, and all analytical and diagnostics investigations involve a water environment.
authors.affiliation: REQUIMTE, Department of Chemistry, FCT-UNL, 2829-516 Monte de Caparica, Portugal.
authors.forename: Elisabete
authors.initials: E
authors.lastname: Oliveira
authors.forename: Damiano
authors.initials: D
authors.lastname: Genovese
authors.forename: Riccardo
authors.initials: R
authors.lastname: Juris
authors.forename: Nelsi
authors.initials: N
authors.lastname: Zaccheroni
authors.forename: José Luis
authors.initials: JL
authors.lastname: Capelo
authors.forename: M Manuela M
authors.initials: MM
authors.lastname: Raposo
authors.forename: Susana P G
authors.initials: SP
authors.lastname: Costa
authors.forename: Luca
authors.initials: L
authors.lastname: Prodi
authors.forename: Carlos
authors.initials: C
authors.lastname: Lodeiro
mesh_terms: D005456:Fluorescent Dyes / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D007477:Ions / Q000032:analysis; D008628:Mercury / Q000032:analysis; D008670:Metals / Q000032:analysis*; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010080:Oxazoles / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D012680:Sensitivity and Specificity; D012822:Silicon Dioxide / Q000737:chemistry; D012834:Silver / Q000032:analysis; D013050:Spectrometry, Fluorescence / Q000379:methods; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods
chemical_list: D005456:Fluorescent Dyes; D007477:Ions; D008670:Metals; D010080:Oxazoles; D010455:Peptides; D012834:Silver; D006046:Gold; D012822:Silicon Dioxide; D008628:Mercury