Fluorescence-tunable copper nanoclusters and their application in hexavalent chromium sensing

Area of Science:

• Materials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Traditional metal nanoclusters often use single ligands, limiting their properties and applications.
• Developing multifunctional nanomaterials requires innovative synthetic strategies.

Purpose of the Study:

• To synthesize novel bi-ligand copper nanoclusters (Cu NCs) using a facile one-pot method.
• To investigate the influence of ligand ratio on Cu NC properties and fluorescence.
• To evaluate the application of these Cu NCs as fluorescent probes for detecting hexavalent chromium.

Main Methods:

• A one-pot synthesis of bi-ligand Cu NCs using copper ions, thiosalicylic acid, and cysteamine.
• Characterization of Cu NCs, including fluorescence quantum yield and photostability measurements.
• Application of Cu NCs in inner-filter-effect-based detection of hexavalent chromium (Cr(VI)).

Main Results:

• Synthesized bi-ligand Cu NCs with high quantum yields (>18.9%) and good photostability.
• Demonstrated tunable fluorescence intensity and surface properties by adjusting the ligand ratio.
• Achieved sensitive detection of Cr(VI) with a wide linear range (0.1–1000 μM) and a low detection limit (0.03 μM).
• Validated the assay's practical utility with high recoveries (98.3–105.0%) and low relative standard deviations (<4.54%) in real sample analysis.

Conclusions:

• Bi-ligand Cu NCs offer enhanced and tunable properties compared to single-ligand counterparts.
• The developed Cu NCs are promising fluorescent probes for sensitive and selective detection of Cr(VI) in environmental samples.
• This work provides a versatile platform for designing advanced nanomaterials with tailored functionalities.