Related Experiment Video
Updated: Feb 17, 2026
Detection of Endotoxin in Nano-formulations Using Limulus Amoebocyte Lysate LAL Assays
Published on: January 30, 2019
A polymyxin B-silver nanoparticle colloidal system and the application of lipopolysaccharide analysis
Tao Liu1, Liqian Gao, Jing Zhao
1CAS Key Lab of Bio-Medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, China. miaopeng@sibet.ac.cn tangyg@sibet.ac.cn.
Abstract:
Polymyxin B (PMB) is a small cyclic polycationic lipopeptide, which can be used as an antibiotic drug against Gram-negative bacteria. In this work, the interaction between citrate capped silver nanoparticles (AgNPs) and PMB is studied. Experimental results show that the association constant is extremely high and the binding event leads to a significant variation in the localized surface plasmon resonance (LSPR) of AgNPs. Moreover, the PMB-AgNP colloidal system can be further exploited as a sensitive analytical platform. Taking lipopolysaccharide (LPS) as an example, we demonstrate a facile colorimetric LPS detection method. LPS is a major constituent of the Gram-negative bacterial cell wall which is used as an optimal biomarker for some diseases like urinary tract infections and sepsis. In this study, target LPS is able to tightly bind to PMB, which effectively inhibits the PMB induced aggregation of AgNPs. By monitoring the UV-vis absorption spectra, the LPS concentration can be quantitatively determined with high sensitivity. The sensing strategy is quite simple, which allows effortless diagnosis of many diseases at different stages.
Insights
Polymyxin B (PMB) strongly binds to silver nanoparticles (AgNPs), creating a sensor. This sensor detects lipopolysaccharide (LPS), a bacterial biomarker, enabling sensitive disease diagnosis.
Area of Science:
- Nanotechnology
- Analytical Chemistry
- Biomedical Science
Background:
- Polymyxin B (PMB) is a lipopeptide antibiotic effective against Gram-negative bacteria.
- Silver nanoparticles (AgNPs) exhibit unique optical properties due to localized surface plasmon resonance (LSPR).
- Lipopolysaccharide (LPS) is a key component of Gram-negative bacterial cell walls and a biomarker for infections like sepsis.
Purpose of the Study:
- To investigate the interaction between citrate-capped AgNPs and PMB.
- To develop a sensitive analytical platform using the PMB-AgNP system.
- To demonstrate a colorimetric method for LPS detection.
Main Methods:
- Characterization of AgNPs and their interaction with PMB.
- Utilizing LSPR variations to monitor binding events.
- Developing a colorimetric assay based on PMB-induced AgNP aggregation inhibition by LPS.
Main Results:
- A high association constant was observed between PMB and AgNPs.
- PMB binding significantly altered the LSPR of AgNPs.
- The PMB-AgNP system successfully detected LPS with high sensitivity via colorimetry.
- LPS binding to PMB inhibited AgNP aggregation, allowing for quantitative analysis.
Conclusions:
- The PMB-AgNP interaction forms a robust foundation for a novel analytical platform.
- The developed colorimetric method offers a simple and sensitive approach for LPS detection.
- This sensing strategy holds potential for early disease diagnosis and monitoring.
More Related Videos
08:29Au-Interaction of Slp1 Polymers and Monolayer from Lysinibacillus sphaericus JG-B53 - QCM-D, ICP-MS and AFM as Tools for Biomolecule-metal Studies
Published on: January 19, 2016
05:31Purification and Visualization of Lipopolysaccharide from Gram-negative Bacteria by Hot Aqueous-phenol Extraction
Published on: May 28, 2012
