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

Area of Science:

• Nanotechnology
• Analytical Chemistry
• Materials Science

Background:

• Quantum dots (QDs) offer unique optical properties for sensing applications.
• Developing selective and sensitive probes for heavy metal ions like copper(II) is crucial for environmental and health monitoring.
• Functionalization of QDs can enhance their specificity and detection capabilities.

Purpose of the Study:

• To synthesize and characterize boronic acid-functionalized cadmium telluride quantum dots (CdTe QDs).
• To develop a novel fluorescent probe for the sensitive and selective detection of copper(II) ions.
• To evaluate the probe's performance in real-world sample matrices such as human serum and water.

Main Methods:

• Synthesis of water-soluble CdTe QDs capped with 3-mercaptopropionic acid.
• Modification of CdTe QDs with 3-aminophenylboronic acid to create boronic acid-functionalized QDs.
• Fluorescence spectroscopy for characterizing QD emission and quantifying copper(II) based on fluorescence quenching.

Main Results:

• The modified QDs exhibited yellow fluorescence (emission peak at 566 nm) upon excitation at 350 nm.
• A linear correlation was observed between fluorescence quenching and copper(II) concentration in the range of 0.01 to 20 μM.
• A low detection limit of 7.6 nM for copper(II) was achieved.
• Satisfactory results were obtained when applying the probe to spiked human serum and water samples.

Conclusions:

• Boronic acid-functionalized CdTe QDs serve as an effective fluorescent probe for copper(II) detection.
• The developed method demonstrates high sensitivity and selectivity for copper(II) determination.
• The probe's applicability in complex matrices highlights its potential for practical environmental and clinical analysis.