Colorimetric Sensor Based on Ag-Fe NTs for H₂S Sensing.

Area of Science:

• Materials Science
• Food Science
• Analytical Chemistry

Background:

• Meat spoilage is a significant concern, often indicated by microbial growth and the production of volatile compounds.
• Volatile sulfides, such as hydrogen sulfide (H2S), are key indicators of meat freshness and spoilage.
• Current methods for freshness detection can be time-consuming or destructive, limiting real-time monitoring during distribution and storage.

Purpose of the Study:

• To develop novel silver-iron nanotriangles (Ag-Fe NTs) for the sensitive detection of hydrogen sulfide (H2S).
• To integrate Ag-Fe NTs into a food packaging system for rapid, real-time, and nondestructive freshness assessment of chilled broiler poultry.
• To establish a visual indicator for meat spoilage based on the colorimetric response to volatile sulfides.

Main Methods:

• Synthesis of silver-iron nanotriangles (Ag-Fe NTs) using a one-pot facile reflux reaction.
• Incorporation of Ag-Fe NTs into a food packaging material.
• Colorimetric detection of H2S based on the etching of Ag-Fe NTs, leading to a color change from yellow to brown.
• Quantification of H2S detection limits using naked eye observation and UV-vis spectrophotometry.

Main Results:

• Successfully synthesized Ag-Fe NTs with potential for H2S detection.
• Demonstrated the integration of Ag-Fe NTs into a functional food packaging system.
• Observed a clear color change (yellow to brown) in the presence of increasing volatile sulfide concentrations.
• Achieved a minimum detection limit of 4 mg/m³ for H2S by naked eye and 2 mg/m³ using UV-vis spectrophotometry.
• Validated the system for real-time, nondestructive monitoring of chilled broiler meat spoilage.

Conclusions:

• Ag-Fe NTs are effective for the visual and quantitative detection of H2S, a key spoilage indicator in meat.
• The developed Ag-Fe NT-based packaging offers a practical and economical solution for real-time monitoring of chilled poultry freshness.
• This technology has the potential to reduce food waste and enhance food safety throughout the supply chain.