title: pH-sensitive Photoluminescence of CdSe/ZnSe/ZnS Quantum Dots in Human Ovarian Cancer Cells.
abstract: The photoluminescence of mercaptoacetic acid (MAA)-capped CdSe/ZnSe/ZnS semiconductor nanocrystal quantum dots (QDs) in SKOV-3 human ovarian cancer cells is pH-dependent, suggesting applications in which QDs serve as intracellular pH sensors. In both fixed and living cells the fluorescence intensity of intracellular MAA-capped QDs (MAA QDs) increases monotonically with increasing pH. The electrophoretic mobility of MAA QDs also increases with pH, indicating an association between surface charging and fluorescence emission. MAA dissociates from the ZnS outer shell at low pH, resulting in aggregation and loss of solubility, and this may also contribute to the MAA QD fluorescence changes observed in the intracellular environment.
authors.affiliation: Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089.
authors.forename: Yu-San
authors.initials: YS
authors.lastname: Liu
authors.forename: Yinghua
authors.initials: Y
authors.lastname: Sun
authors.forename: P Thomas
authors.initials: PT
authors.lastname: Vernier
authors.forename: Chi-Hui
authors.initials: CH
authors.lastname: Liang
authors.forename: Suet Ying Christin
authors.initials: SY
authors.lastname: Chong
authors.forename: Martin A
authors.initials: MA
authors.lastname: Gundersen