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%).