Quenching of chlorophyll fluorescence induced by silver nanoparticles.
The interaction between chlorophyll (Chl) and silver nanoparticles (AgNPs) was evaluated by analyzing the optical behavior of Chl molecules surrounded by different concentrations of AgNPs (10, 60, and 100nm of diameter). UV-Vis absorption, steady state and time-resolved fluorescence measurements were performed for Chl in the presence and absence of these nanoparticles. AgNPs strongly suppressed the Chl fluorescence intensity at 678nm. The Stern-Volmer constant (KSV) showed that fluorescence suppression is driven by the dynamic quenching process. In particular, KSV was nanoparticle size-dependent with an exponential decrease as a function of the nanoparticle diameter. Finally, changes in the Chl fluorescence lifetime in the presence of nanoparticles demonstrated that the fluorescence quenching may be induced by the excited electron transfer from the Chl molecules to the metal nanoparticles.
Grupo de Óptica e Fotônica, Instituto de Física, Universidade Federal de Mato Grosso do Sul, CP 549, 79070-900 Campo Grande, MS, Brazil; Grupo de Óptica Aplicada, Universidade Federal da Grande Dourados, CP 533, 79804-970 Dourados, MS, Brazil.
A M
AM
Queiroz
Grupo de Óptica Aplicada, Universidade Federal da Grande Dourados, CP 533, 79804-970 Dourados, MS, Brazil.
A V
AV
Mezacasa
Grupo de Óptica Aplicada, Universidade Federal da Grande Dourados, CP 533, 79804-970 Dourados, MS, Brazil.
D E
DE
Graciano
Grupo de Óptica Aplicada, Universidade Federal da Grande Dourados, CP 533, 79804-970 Dourados, MS, Brazil.
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WF
Falco
Instituto de Física de São Carlos, Universidade de São Paulo, CP 369, 13560-970 São Carlos, SP, Brazil.
J-C
JC
M'Peko
Instituto de Física de São Carlos, Universidade de São Paulo, CP 369, 13560-970 São Carlos, SP, Brazil.
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FEG
Guimarães
School of Biological Sciences, University of Essex, Wivenhoe Park, CO4 3SQ Colchester, Essex, United Kingdom.
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T
Lawson
School of Biological Sciences, University of Essex, Wivenhoe Park, CO4 3SQ Colchester, Essex, United Kingdom.
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I
Colbeck
Grupo de Óptica e Fotônica, Instituto de Física, Universidade Federal de Mato Grosso do Sul, CP 549, 79070-900 Campo Grande, MS, Brazil.
S L
SL
Oliveira
Grupo de Óptica e Fotônica, Instituto de Física, Universidade Federal de Mato Grosso do Sul, CP 549, 79070-900 Campo Grande, MS, Brazil. Electronic address: anderson.caires@ufms.br.
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ARL
Caires
Chlorophyll; Fluorescence; Lifetime; Nanoparticle; Quenching; Silver