A Ratiometric Fluorescent Sensor for Penicillin G Based on Color-Tunable Gold-Silver Nanoclusters.

Area of Science:

• Nanomaterials Science
• Analytical Chemistry
• Biomedical Engineering

Background:

• Penicillin G residues pose health risks, necessitating effective monitoring methods.
• Existing detection techniques may lack convenience or selectivity.
• Development of rapid, sensitive sensors is crucial for public health.

Purpose of the Study:

• To synthesize and characterize novel gold-silver nanoclusters (AuAgNCs) for penicillin G detection.
• To develop a highly selective and sensitive fluorescence-based sensor for penicillin G.
• To validate the sensor's performance in real-world environmental and clinical samples.

Main Methods:

• Synthesis of AuAgNCs using chicken egg white and 6-aza-2-thiothymine as dual ligands.
• Characterization of AuAgNCs using TEM, XPS, UV-Vis, and fluorescence spectrophotometry.
• Development of a fluorescence quenching assay for quantitative penicillin G detection.

Main Results:

• AuAgNCs exhibited strong yellow fluorescence at 509 and 689 nm.
• Linear fluorescence quenching observed with penicillin G concentrations from 0.2 to 6 μM.
• Achieved a low detection limit of 18 nM with high recoveries (99.7–104.0%) in real samples.
• Sensor detected penicillin G in urine and water samples within 10 minutes.

Conclusions:

• The developed AuAgNC-based sensor offers a rapid, selective, and sensitive method for penicillin G detection.
• Aggregation-induced fluorescence quenching is the primary detection mechanism.
• The sensor is suitable for monitoring penicillin G in environmental and clinical settings.