Metallic nanoparticles became subject of intensive research because of their potential antibiotic properties. Nanoparticles such as silver, gold or zinc oxide particles are easily and cost-effectively synthesized by blending metal salts with plant extracts that reduce the metal. Different extracts, varying in the plant or the part of the plant used for the extract, are currently investigated in regard to their capacity to form nanoparticles and their antimicrobial efficacy. The formation of nanoparticles can be verified by UV-Vis spectroscopy due to surface plasmon resonance of the particles that lead to a characteristic spectrum defined by the underlying metal and particle size. Subsequent analysis of nanoparticles on microbial growth is typically tested by methods based on absorbance changes.
Here, we present how the spectrometer-based BMG LABTECH instruments are used to quickly confirm Ag and ZnO nanoparticle formation and their inhibitory effect on the diarrhea-causing bacteria Vibrio cholerae and enterotoxic Escherichia coli (ETEC).