Durable, recyclable, and stretchable plasmonic film for grapefruit decay detection

Area of Science:

• Materials Science
• Analytical Chemistry
• Food Science

Background:

• Flexible surface-enhanced Raman scattering (SERS) sensors are promising for non-destructive fruit quality monitoring.
• Current SERS substrates lack the operational stability needed for long-term agricultural storage.

Purpose of the Study:

• To develop a durable, recyclable, and stretchable plasmonic film for decay detection in grapefruits.
• To assess the sensor's sensitivity, mechanical resilience, and long-term stability.

Main Methods:

• Fabrication of a composite film (Au@AgNWs/PDMS) by embedding silver nanowires in PDMS and functionalizing with gold nanoparticles.
• Testing SERS sensitivity using rhodamine 6G, mechanical strain tolerance, and stability over time.
• In situ tracking of fungal biomarkers on grapefruit surfaces to correlate with decay.

Main Results:

• The Au@AgNWs/PDMS film demonstrated high sensitivity (10⁻⁹ M), 85% tensile strain tolerance, and 49 days of stability.
• The substrate maintained stable SERS performance through 1000 stretching cycles and five regeneration cycles.
• Successful in situ detection of fungal biomarkers and correlation with grapefruit decay progression.

Conclusions:

• The developed plasmonic film offers a robust and reusable SERS substrate for non-destructive fruit decay monitoring.
• This technology provides a scalable solution for improving food security in agricultural storage systems.
• The sensor's durability and reusability address limitations of current SERS technologies for practical applications.