Fluorometric determination of copper(II) by using 3-aminophenylboronic acid-functionalized CdTe quantum dot probes

Water-soluble cadmium telluride quantum dots capped with 3-mercaptopropionic acid were synthesized and further modified with 3-aminophenylboronic acid to form boronic acid-functionalized quantum dots (QDs). Under excitation at 350 nm, the modified QDs display yellow fluorescence with a peak at 566 nm. On exposure to copper(II), the fluorescence of the QDs is quenched. Under optimal conditions, fluorescence drops linearly in the 0.01 to 20 μM Cu(II) concentration range, and the detection limit is 7.6 nM. This fluorescent probe was applied to the determination of Cu(II) in spiked human serum and water samples and gave satisfactory results. Graphical abstract Schematic presentation of the principle for fluorometrice detection of copper(II) based on the use of boronic acid-functionalized cadmium telluride quantum dots (CdTe QDs).