Open AccessInvestigation of pH-dependent photophysical properties of quantum nanocrystals by fluorescence correlation spectroscopy
Author(s) -
Makoto Oura,
Johtaro Yamamoto,
Takashi Jin,
Masataka Kinjo
Publication year - 2017
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.25.001435
Subject(s) - microsecond , fluorescence , fluorescence correlation spectroscopy , nanocrystal , nanosecond , materials science , spectroscopy , quantum dot , relaxation (psychology) , fluorescence spectroscopy , optics , optoelectronics , nanotechnology , physics , laser , psychology , social psychology , quantum mechanics
Quantum dot (QD) and quantum rod (QR) nanocrystals are widely used non-organic nanocrystals. Their strong fluorescence and photostability make them suitable for biomedical imaging applications. However, their pH-dependence and antibunching properties have not been studied much, especially in aqueous conditions. In this report, we used fluorescence correlation spectroscopy (FCS) with high temporal resolution to demonstrate that the fluorescent blinking and antibunching of QDs/QRs can be changed by varying the pH of their solutions. Furthermore, herein, we reported the relationship between the aggregation and antibunching relaxation time of QDs/QRs for the first time. The findings of this study suggest that FCS can be used to discover novel environmental indicators via observing nanosecond and microsecond phenomena.