Aptamer-Based Impedimetric Sensor for Bacterial Typing

作者：Labib Mahmoud; Zamay Anna S; Kolovskaya Olga S; Reshetneva Irina T; Zamay Galina S; Kibbee Richard J; Sattar Syed A; Zamay Tatiana N; Berezovski Maxim V^*

来源：Analytical Chemistry, 2012, 84(19): 8114-8117.

DOI：10.1021/ac302217u

The development of an aptamer-based impedimetric sensor for typing of bacteria (AIST-B) is presented. Highly specific DNA aptamers to Salmonella enteritidis were selected via Cell-SELEX technique. Twelve rounds of selection were performed; each comprises a positive selection step against S. enteritidis and a negative selection step against a mixture of related pathogens, including Salmonella typhimurium, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Citrobacter freundii, to ensure the species-specificity of the selected aptamers. After sequencing of the pool showing the highest binding affinity to S. enteritidis, a DNA sequence of high affinity to the bacteria was integrated into an impedimetric sensor via self-assembly onto a gold nanoparticles-modified screen-printed electrode (GNPs-SPCE). Remarkably, this aptasensor is highly selective and can successfully detect S. enteritidis down to 600 CFU mL(-1) (equivalent to 18 CFU in 30 mu L, assay volume) in 10 min and distinguish it from other Salmonella species, including S. typhimurium and S. choleraesuis. This report is envisaged to open a new venue for the aptamer-based typing of a variety of microorganisms using a rapid, economic, and label-free electrochemical platform.

• 出版日期2012-10-2