Ultra-stable L-proline protected copper nanoclusters and their solvent effect.

Area of Science:

• Materials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Copper nanoclusters (Cu NCs) are prone to oxidation, limiting their practical applications.
• Developing stable and functional Cu NCs is crucial for their use in sensing and imaging.

Purpose of the Study:

• To synthesize and characterize ultra-stable, water-soluble L-proline-protected copper nanoclusters (Cu NCs).
• To investigate the stability, pH-dependent fluorescence, and solvent-dependent properties of the as-prepared Cu NCs.

Main Methods:

• Synthesis of L-proline-protected copper nanoclusters.
• Characterization of Cu NCs size using (± standard deviation) measurements.
• Assessment of Cu NCs stability under various conditions (pH, storage, ionic strength, H2O2, metal ions).
• Evaluation of pH-dependent and solvent-dependent fluorescence properties.

Main Results:

• Successfully synthesized water-soluble and ultra-stable Cu NCs with an average size of 1.88 ± 0.17 nm.
• Demonstrated excellent stability across a wide pH range, long-term storage, high ionic strength, and in the presence of hydrogen peroxide and metal ions.
• Observed reversible, pH-dependent fluorescence changes between pH 9 and 13 over 8 cycles.
• Reported solvent-dependent emission color changes (blue to green/yellow) in dimethyl sulfoxide and ethylenediamine.

Conclusions:

• L-proline protection confers exceptional stability to copper nanoclusters, overcoming oxidation issues.
• The unique and reversible fluorescence properties of these Cu NCs make them promising candidates for analytical probes.
• The developed Cu NCs offer potential for novel sensing and diagnostic applications.