Posted: November 14, 2007

Magnetic nanoparticles detect and remove harmful bacteria

(Nanowerk News) Researchers in Ohio report the development of magnetic nanoparticles that show promise for quickly detecting and eliminating E. coli, anthrax, and other harmful bacteria. In laboratory studies, the nanoparticles helped detect a strain of E. coli within five minutes and removed 88 percent of the target bacteria, the scientists say. Their study is scheduled for the Nov. 7 issue of the Journal of the American Chemical Society, a weekly publication ("Magnetic Glyco-nanoparticles: A Unique Tool for Rapid Pathogen Detection, Decontamination, and Strain Differentiation"). 
Xuefei Huang and colleagues point out that ongoing incidents of produce contamination and the threat of bioterrorist attacks have created an urgent need for quicker, more effective ways to detect bacterial decontamination. To meet that need, they developed a "magnetic glyco-nanoparticle (MGNP)," a unique compound that combines magnetic nanoparticles with sugars.  
Sugars (or carbohydrates) on cell surfaces are used by many bacteria to attach to their host cells in order to facilitate infection. The scientists exposed a group of E. coli bacteria to the sugar-coated nano-magnets to mark the microbes so they could be easily identified and removed by a magnetic device. The researchers also used the particles to distinguish between three different E. coli strains.  
The study represents "the first time that magnetic nanoparticles have been used to detect, quantify, and differentiate E. coli cells," the researchers state.
American Chemical Society