Laboratory study demonstrates naked-eye detection of single-digit pathogens and attomolar antibodies in food and water, highlighting a highly sensitive alternative to standard immunoassays.
We introduce an enzyme-free plasmonic immunoassay with a binary (all-or-none) response. The presence of a single pathogen in the sample results in a chemical cascade reaction leading to a large red to dark-blue colorimetric shift visible to the naked eye. The immediate and amplified response is initiated by a triggered breakdown of cysteine-loaded nanoliposomes and subsequent aggregation of plasmonic gold nanoparticles. Our approach enabled visual detection of a single-digit live pathogen of Salmonella, Listeria, and E. coli O157 in water and food samples. Furthermore, the assay allowed a naked-eye detection of target antibody concentrations as low as 6.7 attomolar (600 molecules in 150 μL); six orders of magnitude lower than conventional enzyme-linked immunosorbent assay (ELISA).
No takes yet. Share an insight, caveat, or question.
Bui et al. (2015) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: