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Updated: Jul 19, 2026
A Fluorescence Fluctuation Spectroscopy Assay of Protein-Protein Interactions at Cell-Cell Contacts
Published on: December 1, 2018
Photoinduced fluorescence intensity oscillation in a reaction-diffusion cell containing a colloidal quantum dot
Atsushi Komoto1, Shinya Maenosono
1Department of Chemical System Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan. komoto@chemsys.t.u-tokyo.ac.jp
Abstract:
The nonlinear spontaneous oscillation of photoluminescence (PL) intensity in an ensemble of semiconductor quantum dots (QDs), which differs from the fluorescence intermittency of a single QD, is investigated. The PL intensity in a QD dispersion slowly oscillates with time under continuous illumination. The oscillatory behavior is found to vary with changing QD concentration, solvent viscosity, volume fraction of irradiated region, and irradiation intensity. On the basis of the Gray-Scott model [Chemical Oscillation and Instabilities: Non-linear Chemical Kinetics (Clarendon, Oxford, 1994); J. Phys. Chem. 89, 22 (1985); Chem. Eng. Sci. 42, 307 (1987)], and its comparison with the experimental results, it is revealed that the following processes are important for PL oscillation: (1) mass transfer of QDs between the illuminated and dark regions, (2) autocatalytic formation of vacant sites on QD surfaces via photodesorption of ligand molecules, and (3) passivation of vacant sites via photoadsorption of water molecules.
