Synthesis of high-quality water-soluble near-infrared-emitting CdTe quantum dots capped with 3-mercaptobutyric acid.
Highly fluorescent CdTe quantum dots (QDs) with emission in red to near-infrared (NIR) wavelength were successfully prepared by using 3-mercaptobutyric acid (3MBA) as capping agent. The maximum of quantum yield (QY) could reach up to 82% for QDs with emission peak at 686 nm and FWHM of 66 nm at optimal conditions. The QY of these QDs could maintain above 65% in the 650-750 nm region and QDs with emission over 800 nm were still strong fluorescent (28-41%). These optical properties of CdTe quantum dots are among the best results prepared by the state-of-the-art methods, suggesting their promising applications in bio-imaging. The success of 3MBA as excellent capping agent in this method was attributed to the balanced chain length and methyl side chain in comparison to a series of linear and branched mercapto acids, namely thioglycolic acid, thiolactic acid, 3-mercaptopropionic acid, 4-mercaptobutyric acid, 5-mercaptovaleric acid, 4-mercaptovaleric acid and 3-mercapto-2-methylbutyric acid.
Kai-Guo
KG
Ma
Jin-Yi
JY
Bai
Tan
T
Fang
Hai-Qing
HQ
Guo
D002087:Butyrates / Q000737:chemistry*; D019187:Cadmium Compounds / Q000737:chemistry*; D003460:Crystallization / Q000379:methods; D007259:Infrared Rays; D008422:Materials Testing; D010316:Particle Size; D045663:Quantum Dots; D012995:Solubility; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013691:Tellurium / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
D002087:Butyrates; D019187:Cadmium Compounds; D014867:Water; C067656:4-mercaptobutyrate; D013691:Tellurium; C028337:cadmium telluride