Copper quantum clusters in protein matrix: potential sensor of Pb2+ ion

Area of Science:

• Nanotechnology
• Biomaterials Science
• Analytical Chemistry

Background:

• Quantum clusters (QCs) offer unique optical and electronic properties.
• Protein capping provides stability and water solubility to nanomaterials.
• Developing sensitive and selective sensors for environmental and biological analytes is crucial.

Purpose of the Study:

• To synthesize stable, water-soluble copper quantum clusters (Cu QCs) using bovine serum albumin (BSA).
• To characterize the composition and luminescence properties of the synthesized Cu QCs.
• To evaluate the potential of these Cu QCs as sensing materials for hydrogen peroxide and lead ions.

Main Methods:

• One-pot synthesis of Cu QCs capped with BSA.
• Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry for core composition analysis.
• Luminescence spectroscopy to determine optical properties and sensing capabilities.
• Testing detection limits for hydrogen peroxide and lead (Pb2+) ions.

Main Results:

• Extremely stable, water-soluble Cu QCs with Cu(5) and Cu(13) cores were successfully synthesized.
• Cu QCs exhibited distinct luminescence properties (excitation/emission maxima at 325/410 nm, quantum yield 0.15).
• Luminescence quenching detected nanomolar hydrogen peroxide, and selective detection of part-per-million Pb2+ ions was achieved without interference.

Conclusions:

• BSA-capped Cu QCs are highly stable and water-soluble nanomaterials.
• The developed Cu QCs show significant potential as sensitive and selective sensors for biological and environmental monitoring.
• This work highlights the utility of protein-templated QCs in advanced sensing applications.