Novel strategy combining SYBR Green I with carbon nanotubes for highly sensitive detection of Salmonella typhimurium DNA
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- 作者：Pingdao Mao ; Yi Ning ; Wenkai Li ; Zhihui Peng ; Yongzhe Chen ; Le Deng
- 关键词：Salmonella typhimurium ; SYBR Green I ; SWNTs ; Nucleic acid detection
- 刊名：Enzyme and Microbial Technology
- 出版年：10 January, 2014
- 年：2014
- 卷：54
- 期：Complete
- 页码：15-19
- 全文大小：1155 K
文摘
A simple, selective, sensitive and label-free fluorescent method for detecting trpS-harboring Salmonella typhimurium was developed in this study. This assay used the non-covalent interaction of single-stranded DNA (ssDNA) probes with SWNTs, since SWNTs can quench fluorescence. Fluorescence recovery (78% with 1.8 nM target DNA) was detected in the presence of target DNA as ssDNA probes detached from SWNTs hybridized with target DNA, and the resulting double-stranded DNA (dsDNA) intercalated with SYBR Green I (SG) dyes. The increasing fluorescence intensity reached 4.54-fold. In contrast, mismatched oligonucleotides (1- or 3-nt difference to the target DNA) did not contribute to significant fluorescent recovery, which demonstrated the specificity of the assay. The increasing fluorescence intensity increased 3.15-fold when purified PCR products containing complementary sequences of trpS gene were detected. These results confirmed the ability to use this assay for detecting real samples.