A polymyxin B–silver nanoparticle colloidal system and the application of lipopolysaccharide analysis. Issue 5 (11th December 2017)

• Record Type: Journal Article
• Authors: Liu, Tao; Gao, Liqian; Zhao, Jing; Cao, Ya; Tang, Yuguo; Miao, Peng
• Is Part Of: Analyst. Volume 143:Issue 5(2018)
• Page Start: 1053
• Page End: 1058
• Publication Date: 2017-12-11
• Subjects: Chemistry, Analytic -- Periodicals; 543
• DOI: 10.1039/c7an01788j
• Languages: English
• ISSNs: 0003-2654

Abstract

Abstract : The association constant between polymyxin B and silver nanoparticles is found to be extremely high. Thus, we have exploited the colloidal system as a universal analytical platform. 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.