Selective and sensitive Escherichia coli detection based on a T4 bacteriophage-immobilized multimode microfiber

Area of Science:

• Biotechnology
• Optics
• Microbiology

Background:

• Escherichia coli (E. coli) outbreaks linked to contaminated food and water pose significant public health risks.
• Accurate and rapid detection methods for E. coli are essential for effective public health interventions.

Purpose of the Study:

• To propose and demonstrate a novel, fast-response, label-free biosensor for detecting E. coli.
• To utilize a multimode microfiber probe for sensitive E. coli quantification.

Main Methods:

• A bacteriophage-based detection strategy was employed.
• A multimode microfiber probe was designed to excite guided modes with evanescent fields.
• Changes in the optical spectrum due to E. coli binding were monitored to quantify concentration.

Main Results:

• The microfiber probe demonstrated reliable detection of E. coli concentrations ranging from 10^3 to 10^7 colony-forming units per milliliter (cfu/mL).
• The sensor achieved a limit of detection as low as 10^3 cfu/mL.
• The method exhibited high sensitivity and a fast response time.

Conclusions:

• The developed bacteriophage-based microfiber probe is a promising tool for rapid and sensitive E. coli detection.
• This technology has significant potential applications in environmental monitoring and food safety assurance.