Thioglucopyranose Ligands Promote Phase-Transfer of Cadmium Selenide Quantum Dots from Organic Solvents to Water

The attainment of water-dispersible cadmium selenide quantum dots (CdSe QDs) with bright luminescence and tunable optical properties represents a great challenge to improve their biological applications. Indeed, over the last years, fluorescent materials have been widely applied for sensing and bioimaging, thus promoting research in the field of life science. Herein, we present the functionalization of CdSe QDs with peracetylated thioglucopyranose (2,3,4,6-Tetra-O-acetyl-1-thio-beta-D-glucopyranose) and the subsequent deprotection reaction. This novel protocol performed at room temperature and under mild conditions allows the phase-transfer of the functionalized nanoparticles from organic solvents into water. The CdSe QDs in water showed higher photoluminescent efficiency than their nanoparticle precursors in organic solvents. Our results represent an effective methodology useful to obtain water-soluble QDs to foster the potential uses for glycobiological studies.