DNA biosensor-based on fluorescence detection of E. coli O157:H7 by Au@Ag nanorods
| Autor: | Xiulan Sun, Yinzhi Zhang, Yanqing Sun, Jian Ji, Mandour H. Abdalhai, Jiadi Sun |
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| Rok vydání: | 2014 |
| Předmět: |
DNA
Bacterial Silver Biomedical Engineering Biophysics Analytical chemistry Metal Nanoparticles medicine.disease_cause Escherichia coli O157 Sensitivity and Specificity chemistry.chemical_compound Electrochemistry medicine Adhesins Bacterial Escherichia coli Detection limit Nanotubes Chemistry Hybridization probe Escherichia coli Proteins Reproducibility of Results General Medicine Fluorescence Spectrometry Fluorescence Linear range Nanorod Gold DNA Probes Biosensor DNA Biotechnology |
| Zdroj: | Biosensorsbioelectronics. 70 |
| ISSN: | 1873-4235 |
| Popis: | A novel DNA sensor for the detection of the Escherichia coli O157:H7 (E. coli O157:H7) eaeA gene was constructed using surface enhanced fluorescence (SEF). The spacing distance dependence nature of Au@Ag nanorods surface enhanced fluorescence was investigated when the cy3-labled single strand DNA(ssDNA) and the stem-loop DNA probe modified on the nanorods was co-hybridized. The result revealed that the fluorescence intensity reached the maximum value with the spacing distance of about 10 nm between cy3 and the Au@Ag nanorods surface. Based on this result, a fluorescence “ON/OFF” switch for detecting the eaeA gene of E. coli O157:H7 was constructed. Under optimal conditions, the DNA sensor produced a linear range from 10−17 to 10−11 M with a correlation coefficient of 0.9947 and a detection limit of 3.33×10−18 M, and was also found to be specific in targeting eaeA. The DNA sensor demonstrated a new strategy of combining eaeA recognition and Au@Ag nanorods for fluorescence signal enhancement, and increased sensitivity in the detection of bacterial specific genes. |
| Databáze: | OpenAIRE |
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