title: Photoreactivity of a quantum dot-ruthenium nitrosyl conjugate.
abstract: We describe the use of cadmium telluride quantum dots (CdTe QDs) as antennas for the photosensitization of nitric oxide release from a ruthenium nitrosyl complex with visible light excitation. The CdTe QDs were capped with mercaptopropionic acid to make them water-soluble, and the ruthenium nitrosyl complex was cis-[Ru(NO)(4-ampy)(bpy)2](3+) (Ru-NO; bpy is 2,2'-bipyridine, and 4-ampy is 4-aminopyridine). Solutions of these two components demonstrated concentration-dependent quenching of the QD photoluminescence (PL) as well as photoinduced release of NO from Ru-NO when irradiated by 530 nm light. A NO release enhancement of ∼8 times resulting from this association was observed under longer wavelength excitation in visible light range. The dynamics of the quenching determined by both PL and transient absorption measurements were probed by ultrafast flash photolysis. A charge transfer mechanism is proposed to explain the quenching of the QD excited states as well as the photosensitized release of NO from Ru-NO.
authors.affiliation: Faculdade de Ciências Farmacêuticas de Ribeirão Preto, University of Sao Paulo , Avenida do Café s/n, 14040-903 Ribeirão Preto, Sao Paulo, Brazil.
authors.forename: Lilian Pereira
authors.initials: LP
authors.lastname: Franco
authors.forename: Simone Aparecida
authors.initials: SA
authors.lastname: Cicillini
authors.forename: Juliana Cristina
authors.initials: JC
authors.lastname: Biazzotto
authors.forename: Marco A
authors.initials: MA
authors.lastname: Schiavon
authors.forename: Alexander
authors.initials: A
authors.lastname: Mikhailovsky
authors.forename: Peter
authors.initials: P
authors.lastname: Burks
authors.forename: John
authors.initials: J
authors.lastname: Garcia
authors.forename: Peter C
authors.initials: PC
authors.lastname: Ford
authors.forename: Roberto Santana
authors.initials: RS
authors.lastname: da Silva
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry; D009589:Nitrogen Oxides / Q000737:chemistry*; D055668:Photochemical Processes; D045663:Quantum Dots / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry*; D013691:Tellurium / Q000737:chemistry
chemical_list: D019187:Cadmium Compounds; D009589:Nitrogen Oxides; D012428:Ruthenium; D013691:Tellurium; C028337:cadmium telluride