Cooperative effects in CdSe/ZnS-PEGOH quantum dot luminescence quenching by a water soluble porphyrin

Autor(es)

Borissevitch, I. E. ^[1] ; Parra, G. G. ^[1] ; Zagidullin, V. E. ^[2] ; Lukashev, E. P. ^[2] ; Knox, P. P. ^[2] ; Paschenko, V. Z. ^[2] ; Rubin, A. B. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto, Dept Fis, BR-14040901 Ribeirao Preto, SP - Brazil

^[2] Moscow MV Lomonosov State Univ, Fac Biol, Dept Biophys, Moscow 119991 - Russia

• Tipo de documento: Artigo Científico
• Fonte: Journal of Luminescence; v. 134, p. 83-87, FEB 2013.
• Citações Web of Science: 12
• Assunto(s): Terapia fotodinâmica Nanocristais Nanopartículas

Resumo

In this work we report on the study of the interaction of CdSe/ZnS-PEGOH 570 Quantum Dot (QD) with negatively charged meso-tetrakis(p-sulfonato-phenyl)porphyrin (TPPS4) using optical absorption and fluorescence spectroscopies accompanied with time resolved ``single photon counting{''} and dynamic and resonance light scattering techniques. In the steady-state experiments the QD luminescence quenching by TPPS4 was well approximated by a square law. In the time-resolved experiments we observed a typical multi-exponential luminescence decay curve, successfully fitted by a bi-exponential approximation. At QD interaction with porphyrin the time quenching of both components was described by a linear Stern-Volmer dependence. The discrepancy between Stern-Volmer dependences in the steady-state and time resolved experiments may be due to formation of mixed m(TPPS4)+n(QD) complexes, in which one TPPS4 molecule can quench several excited QDs. This idea is in accordance with the dynamic and resonance light scattering data, which demonstrate an increase of the scattering particle size at the TPPS4 addition to QD solutions. (c) 2012 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 11/20606-5 - Estudos da interação dos nanocristais semicondutores (Pontos Quânticos) com fotossensibilizadores orgânicos na presença de estruturas nanoorganizadas - modelos de sistemas biológicos
• Beneficiário: Gustavo Gimenez Parra
• Modalidade de apoio: Bolsas no Brasil - Doutorado