Aptamer-based viability impedimetric sensor for bacteria

Mahmoud Labib, Anna S. Zamay, Olga S. Kolovskaya, Irina T. Reshetneva, Galina S. Zamay, Richard J. Kibbee, Syed A. Sattar, Tatiana N. Zamay, Maxim V. Berezovski*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

127 Scopus citations

Abstract

The development of an aptamer-based viability impedimetric sensor for bacteria (AptaVISens-B) is presented. Highly specific DNA aptamers to live Salmonella typhimurium were selected via the cell-systematic evolution of ligands by exponential enrichment (SELEX) technique. Twelve rounds of selection were performed; each comprises a positive selection step against viable S. typhimurium and a negative selection step against heat killed S. typhimurium and a mixture of related pathogens, including Salmonella enteritidis, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Citrobacter freundii to ensure the species specificity of the selected aptamers. The DNA sequence showing the highest binding affinity to the bacteria was further integrated into an impedimetric sensor via self-assembly onto a gold nanoparticle-modified screen-printed carbon electrode (GNP-SPCE). Remarkably, this aptasensor is highly selective and can successfully detect S. typhimurium down to 600 CFU mL-1 (equivalent to 18 live cells in 30 μL of assay volume) and distinguish it from other Salmonella species, including S. enteritidis and S. choleraesuis. This report is envisaged to open a new venue for the aptamer-based viability sensing of a variety of microorganisms, particularly viable but nonculturable (VBNC) bacteria, using a rapid, economic, and label-free electrochemical platform.

Original languageEnglish (US)
Pages (from-to)8966-8969
Number of pages4
JournalAnalytical Chemistry
Volume84
Issue number21
DOIs
StatePublished - Nov 6 2012
Externally publishedYes

ASJC Scopus subject areas

  • Analytical Chemistry

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