title: Investigating the photostability of quantum dots at the single-molecule level.
abstract: Quantum dots (QDs) have shown great potential to provide spatial, temporal, and structural information for biological systems. However, blinking, photobleaching, and spectral blueshift are adverse effects on their practical applications in biomedical research. An investigation of the effects of six reducing agents including cysteine (Cys), 1,4-dithiothreitol (DTT), ethyl gallate (EG), L-glutathione (GSH), mercaptoacetic acid (MAA), and thiourea (TU) on the photostability of single QDs was studied. Our experiments demonstrate that both DTT and EG effectively inhibit blinking, photobleaching, and spectral blueshift. GSH molecules block blinking and photobleaching of QDs. The other reagents, Cys, MAA, and TU, only have the ability to counteract blinking. Possible explanations are given on the basis of research evidence. The results suggest possibilities for significant improvements in QDs for biological applications by adjusting the environmental conditions.
authors.affiliation: School of Chemistry and Chemical Engineering, Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials, Jiangsu Normal University, Xuzhou, Jiangsu (P.R. China), Fax: (+86) 516-83536972.
authors.forename: Wenfeng
authors.initials: W
authors.lastname: Zhao
authors.forename: Suli
authors.initials: S
authors.lastname: Dong
authors.forename: Lichun
authors.initials: L
authors.lastname: Sun
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.forename: Hongwei
authors.initials: H
authors.lastname: Gai
mesh_terms: D003545:Cysteine / Q000737:chemistry; D004229:Dithiothreitol / Q000737:chemistry; D005707:Gallic Acid / Q000031:analogs & derivatives / Q000737:chemistry; D005978:Glutathione / Q000737:chemistry; D038761:Photobleaching; D045663:Quantum Dots; D013864:Thioglycolates / Q000737:chemistry; D013890:Thiourea / Q000737:chemistry
chemical_list: D013864:Thioglycolates; C048734:ethyl gallate; D005707:Gallic Acid; C017487:2-mercaptoacetate; D005978:Glutathione; D013890:Thiourea; D003545:Cysteine; D004229:Dithiothreitol
keywords: blinking; photobleaching; quantum dots; single-molecule studies; spectral blueshift