High-Throughput Analysis of Bacterial Toxic Lipopolysaccharide in Water by Dual-Wavelength Monitoring Using a...

Area of Science:

• Environmental chemistry
• Analytical chemistry
• Biochemistry

Background:

• Lipopolysaccharide (LPS) is a potent bacterial endotoxin known to induce fever in humans.
• Accurate and sensitive detection of LPS is crucial for public health and water quality monitoring.
• Existing detection methods often lack the sensitivity or speed required for real-time analysis.

Purpose of the Study:

• To develop a highly sensitive and rapid fluorescent chemosensor for LPS detection.
• To investigate the sensing mechanism of the chemosensor.
• To integrate the chemosensor into a flow injection analysis (FIA) system for high-throughput monitoring.

Main Methods:

• Synthesis and characterization of the Zn-dpa-C2OPy small-molecule chemosensor.
• Spectroscopic analyses including fluorescence, absorbance, 1H NMR, and fluorescence lifetime measurements.
• Dynamic light scattering (DLS) and transmission electron microscopy (TEM) to study aggregation.
• Integration with a custom-built dual-wavelength fluorophotometer for flow injection analysis (FIA).

Main Results:

• The Zn-dpa-C2OPy chemosensor exhibited a rapid ratiometric fluorescence response to LPS in water.
• Achieved an ultra-low detection limit of 11 pM for LPS, surpassing previous sensors.
• Elucidated the sensing mechanism involving aggregation changes driven by hydrophobic, electrostatic interactions, and zinc(II)-coordination.
• Demonstrated high-throughput analysis (36 samples/hour) using the integrated FIA system.

Conclusions:

• The Zn-dpa-C2OPy chemosensor offers a sensitive and rapid method for LPS detection.
• The developed methodology combining the chemosensor with FIA is feasible for continuous online LPS monitoring in water.
• This approach holds significant potential for water quality assessment and public health protection.