Fabricating Upconversion Fluorescent Probes for Rapidly Sensing Foodborne Pathogens

Area of Science:

• Nanotechnology
• Food Science
• Analytical Chemistry

Background:

• Rare earth-doped upconversion nanoparticles (UCNPs) offer unique optical properties for sensitive detection.
• Food safety relies on rapid and accurate detection of bacterial contaminants like E. coli.
• Existing methods for bacterial detection can be time-consuming or lack sensitivity.

Purpose of the Study:

• To develop a rapid and sensitive bacterium-sensing strategy using UCNPs for food safety applications.
• To create fluorescent probes for the detection of Escherichia coli (E. coli).
• To evaluate the performance of the UCNP-based assay in real food matrices.

Main Methods:

• Fabrication of highly fluorescent and water-soluble UCNPs.
• Conjugation of UCNPs with antibodies specific to E. coli to create fluorescent probes.
• Quantification of E. coli by measuring fluorescence intensity differences after cell capture and pelleting.

Main Results:

• The UCNP-based assay demonstrated a linear response with E. coli concentration from 42 to 42 × 10(6) cfu/mL (R(2) = 0.9802).
• A low limit of detection of 10 cfu/mL was achieved.
• The method successfully detected E. coli in spiked meat and milk samples, confirming its practical applicability.

Conclusions:

• UCNPs provide a sensitive and rapid platform for bacterial detection in food safety.
• The developed antibody-conjugated UCNP probes are effective for detecting E. coli in complex food matrices.
• This UCNP-based strategy holds significant promise for improving food safety monitoring.