This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: A research team led by senior researcher Minyoung Lee and principal researcher Sunggyu Park of the Advanced Bio and Healthcare Materials Research Division at the Korea Institute of Materials Science (KIMS), has developed a label-free surface-enhanced Raman scattering (SERS) analysis technology that rapidly detects extremely low concentrations of viable bacteria by directly growing plasmonic metal nanostructures on and around bacterial cells. The technology enables trace levels of bacteria to be detected within one hour without conventional culture-based amplification and could also assess bacterial responses to antibiotics within two hours.
It is expected to provide a foundation for rapid diagnosis of severe infectious diseases such as sepsis and for more precise selection of antibiotic treatments. The work is published in the journal Small Methods. Sepsis is a life-threatening condition in which the body's dysregulated response to infection leads to organ dysfunction.
Rapid identification of the causative pathogen and timely administration of an effective antibiotic are therefore critical. During the early stages of infection, however, bacterial concentrations in the bloodstream can be extremely low, making direct detection difficult. Conventional blood culture testing requires bacteria in a blood sample to be grown before the causative organism and an appropriate antibiotic can be identified, meaning that final results may take tens of hours or several days.
This has created strong demand for technologies capable of rapidly detecting viable pathogens and determining which antibiotics are effective. KIMS previously developed highly sensitive biosensor technologies that use three-dimensional plasmonic nanostructures to detect protein biomarkers associated with sepsis in blood. The new research goes a step further by directly detecting viable causative bacteria themselves rather than disease-associated biomarkers and by rapidly evaluating their response to antibiotics.
To achieve this, the research team developed a SERS analysis approach in which bacterial cells themselves serve as nucleation sites for nanostructure growth. Plasmonic metal nanostructures are formed directly on and around bacterial cells, creating highly localized electromagnetic enhancement and amplifying the bacteria's intrinsic Raman signals. The researchers progressively advanced the technology through three stages: growing nanostructures around bacteria in solution, directly depositing metal nanostructures onto bacterial surfaces and finally integrating bacterial separation and enrichment with additional in situ nanostructure growth.
This stepwise development substantially improved the ability to detect bacteria at extremely low concentrations. SERS is an analytical technique that amplifies the weak Raman signals characteristic of a material by using intense electromagnetic fields known as plasmonic hot spots, which form in nanoscale gaps between metallic nanostructures such as gold or silver. Conventional SERS approaches face an inherent structural mismatch: plasmonic hot spots are typically only a few to tens of nanometers in size, whereas bacterial cells are approximately one micrometer in scale.
Extract — continue reading at the source.
