Simultaneous aptasensor for multiplex pathogenic bacteria detection based on multicolor upconversion nanoparticles...

Area of Science:

• Nanotechnology
• Biotechnology
• Analytical Chemistry

Background:

• Pathogenic bacteria pose a significant threat to public health and food safety.
• Existing detection methods often lack sensitivity, specificity, or the ability for multiplexed detection.

Purpose of the Study:

• To develop a highly sensitive and specific multiplex method for simultaneous detection of Staphylococcus aureus, Vibrio parahemolyticus, and Salmonella typhimurium.
• To utilize multicolor upconversion nanoparticles (UCNPs) as luminescence labels and aptamers as recognition elements.

Main Methods:

• Synthesized multicolor UCNPs by doping with rare-earth ions for distinct emission peaks.
• Selected specific aptamers for each target bacterium using the SELEX strategy.
• Integrated aptamers and UCNPs for selective capture and simultaneous quantification of bacteria.

Main Results:

• Achieved linear correlation between bacterial concentration (50-10^6 cfu mL⁻¹) and luminescence signal.
• Obtained low limits of detection: 25 cfu mL⁻¹ for S. aureus, 10 cfu mL⁻¹ for V. parahemolyticus, and 15 cfu mL⁻¹ for S. typhimurium.
• Demonstrated successful application in real food samples with results consistent with plate-counting methods.

Conclusions:

• The developed multicolor UCNP-based aptasensor provides a sensitive and specific platform for multiplexed detection of foodborne pathogens.
• This method shows great potential for enhancing food safety monitoring and developing advanced multiplex nanosensors.