Highly Specific and Cost-Efficient Detection of Salmonella Paratyphi A Combining Aptamers with Single-Walled Carbon Nanotubes

Sensors

Ming Yang¹  Zhihui Peng¹  Yi Ning¹  Yongzhe Chen¹  Qin Zhou¹ 

[1] The Co-Construction Laboratory of Microbial Molecular Biology of Province Department and Ministry of Science and Technology, College of Life Sciences, Hunan Normal University, Changsha 410081, China; E-Mail

关键词: Salmonella Paratyphi A;    aptamer;    single-walled carbon nanotubes;    detection;   

DOI  :  10.3390/s130506865

来源: mdpi

【 摘 要 】

In this paper, a panel of single-stranded DNA aptamers with high affinity and specificity against Salmonella Paratyphi A was selected from an enriched oligonucleotide pool by a whole-cell-Systematic Evolution of Ligands by Exponential Enrichment (SELEX) procedure, during which four other Salmonella serovars were used as counter-selection targets. It was determined through a fluorescence assay that the selected aptamers had high binding ability and specificity to this pathogen. The dissociation constant of these aptamers were up to nanomolar range, and aptamer Apt22 with the lowest K_d (47 ± 3 nM) was used in cell imaging experiments. To detect this bacteria with high specificity and cost-efficiently, a novel useful detection method was also constructed based on the noncovalent self-assembly of single-walled carbon nanotubes (SWNTs) and DNAzyme-labeled aptamer detection probes. The amounts of target bacteria could be quantified by exploiting chemoluminescence intensity changes at 420 nm and the detection limit of the method was 10³ cfu/mL. This study demonstrated the applicability of Salmonella specific aptamers and their potential for use in the detection of Salmonella in food, clinical and environmental samples.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.