NaBiF₄ upconversion nanoparticle-based electrochemiluminescent biosensor for E. coli O157 : H7 detection

Area of Science:

• Nanotechnology
• Biosensing
• Analytical Chemistry

Background:

• Foodborne pathogens like E. coli O157:H7 present significant risks to public health.
• Current diagnostic methods for pathogens often lack the required speed, sensitivity, or cost-effectiveness for point-of-care applications.

Purpose of the Study:

• To develop a novel, rapid, and sensitive electrochemiluminescent (ECL) immunosensor for the detection of E. coli O157:H7.
• To synthesize and characterize NaBiF4:Yb3+/Er3+ upconversion nanoparticles (UCNPs) for ECL applications.

Main Methods:

• Synthesized NaBiF4:Yb3+/Er3+ UCNPs via a room-temperature, environmentally friendly method.
• Constructed an ECL immunosensor by assembling Au nanoparticles and Anti-E. coli O157:H7 antibody onto UCNPs.
• Investigated the ECL behaviors of UCNPs with K2S2O8 and evaluated the immunosensor's performance for E. coli O157:H7 detection.

Main Results:

• The synthesized UCNPs exhibited high ECL intensity and stable cathodic signals when combined with K2S2O8.
• The developed ECL immunosensor demonstrated high sensitivity for E. coli O157:H7 detection, with a linear range from 200 to 100,000 CFU mL-1 and a limit of detection of 138 CFU mL-1.
• The biosensor showed excellent specificity, stability, and repeatability.

Conclusions:

• The UCNP-based ECL immunosensor provides a highly sensitive and selective platform for the rapid detection of E. coli O157:H7.
• This strategy holds promise for applications in food safety and preclinical diagnosis, addressing the need for efficient pathogen detection assays.