Detection of endotoxin using an evanescent wave fiber-optic biosensor

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Immunology

Background:

• Lipopolysaccharide (LPS) endotoxin is a potent immune stimulant and a primary cause of sepsis.
• Sepsis leads to over 100,000 deaths annually, highlighting the urgent need for rapid diagnostic methods.
• Current diagnostic techniques for sepsis lack the required speed, reliability, and sensitivity.

Purpose of the Study:

• To develop a rapid and sensitive method for detecting LPS from E. coli.
• To utilize an evanescent wave fiber-optic biosensor for real-time LPS quantification.
• To assess the feasibility of the biosensor in different biological matrices like plasma.

Main Methods:

• Detection of LPS using an evanescent wave fiber-optic biosensor.
• Immobilization of Polymyxin B onto the fiber-optic probe surface for selective LPS binding.
• Employment of a competitive assay format with fluorescently labeled LPS for signal generation.
• Testing the assay in both buffer and plasma to evaluate sensitivity and performance.

Main Results:

• Successful detection of E. coli LPS at concentrations as low as 10 ng/mL within 30 seconds.
• The competitive assay demonstrated similar high sensitivity in both buffer and plasma.
• The fiber-optic biosensor system proved effective for rapid LPS detection.

Conclusions:

• The developed fiber-optic biosensor provides a rapid, sensitive, and reliable method for LPS detection.
• This technology has significant potential for clinical diagnostics of sepsis and environmental monitoring.
• The platform is adaptable for various LPS capture molecules, enabling serotype determination.