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.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000332926400024&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Chemistry, MultidisciplinaryNanoscience & NanotechnologyMaterials Science, MultidisciplinaryPhysics, AppliedPhysics, Condensed MatterSCI(E)1ARTICLE74940-49481