title: Characterization of the interaction of a mono-6-thio-β-cyclodextrin-capped CdTe quantum dots-methylene blue/methylene green system with herring sperm DNA using a spectroscopic approach.
abstract: Novel, water-soluble CdTe quantum dots (QDs) capped with β-cyclodextrin (β-CD) and ~ 4.0 nm in diameter were synthesized in aqueous solution, and characterized using transmission electron microscopy (TEM). A fluorescence-sensing system based on the photoinduced electron transfer (PET) of (mono-6-thio-β-CD)-CdTe QDs was then designed to measure the interaction of phenothiazine dyes [methylene blue (MB) and methylene green (MG)] with herring sperm DNA (hsDNA). This fluorescence-sensing system was based on a fluorescence "OFF-ON" mode. First, MB/MG adsorbed on the surface of (mono-6-thio-β-CD)-CdTe QDs effectively quenches the fluorescence of (mono-6-thio-β-CD)-CdTe QDs through PET. Then, addition of hsDNA restores the fluorescence intensity of (mono-6-thio-β-CD)-CdTe QDs, because hsDNA can bind with MB/MG and remove it from the as-prepared (mono-6-thio-β-CD)-CdTe QDs. In addition, detailed reaction mechanisms of the (mono-6-thio-β-CD)-CdTe QDs-MB/MG-hsDNA solution system were studied using optical methods, by comparison with the TGA-CdTe QDs-MB/MG-hsDNA solution system.
authors.affiliation: Key Laboratory on Luminescence and Real-Time Analysis, School of Chemistry and Chemical Engineering, Southwest University, Chongqing, People's Republic of China.
authors.forename: Yizhong
authors.initials: Y
authors.lastname: Shen
authors.forename: Shaopu
authors.initials: S
authors.lastname: Liu
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Pengfei
authors.initials: P
authors.lastname: Yin
authors.forename: Youqiu
authors.initials: Y
authors.lastname: He
mesh_terms: D000818:Animals; D019187:Cadmium Compounds / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D005399:Fishes; D008297:Male; D008751:Methylene Blue / Q000031:analogs & derivatives* / Q000737:chemistry*; D015394:Molecular Structure; D045663:Quantum Dots; D013050:Spectrometry, Fluorescence; D013094:Spermatozoa / Q000737:chemistry*; D013691:Tellurium / Q000737:chemistry*; D047392:beta-Cyclodextrins / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D019187:Cadmium Compounds; D047392:beta-Cyclodextrins; D004247:DNA; C028673:methylene green; D013691:Tellurium; C028337:cadmium telluride; D008751:Methylene Blue
keywords: (mono-6-thio-β-CD)-CdTe QDs; herring sperm DNA; methylene blue; methylene green; photoinduced electron transfer