A fluorescent aptasensor for Staphylococcus aureus based on strand displacement amplification and self-assembled DNA hexagonal structure
| Autor: | Rongfeng Cai, Fan Yin, Haohan Chen, Yaping Tian, Nandi Zhou |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Staphylococcus aureus
DNA polymerase Aptamer DNA Single-Stranded Food Contamination Biosensing Techniques 02 engineering and technology medicine.disease_cause 01 natural sciences Analytical Chemistry chemistry.chemical_compound Endonuclease Limit of Detection Complementary DNA medicine Animals Fluorescent Dyes Base Sequence biology 010401 analytical chemistry Multiple displacement amplification Aptamers Nucleotide 021001 nanoscience & nanotechnology 0104 chemical sciences Milk Spectrometry Fluorescence chemistry SYBR Green I biology.protein Biophysics Nucleic Acid Conformation 0210 nano-technology Nucleic Acid Amplification Techniques DNA |
| Zdroj: | Microchimica Acta. 187 |
| ISSN: | 1436-5073 0026-3672 |
| DOI: | 10.1007/s00604-020-04293-9 |
| Popis: | A fluorescent aptasensor for Staphylococcus aureus (S. aureus) is designed, which takes advantage of strand displacement amplification (SDA) technology and unique self-assembled DNA hexagonal structure. In the presence of S. aureus, a partially complementary strand of S. aureus aptamer (cDNA) is competitively released from cDNA/aptamer duplex immobilized on magnetic beads due to the affinity of the aptamer for S. aureus. The addition of primer starts the SDA reaction. With the catalysis of Bsm DNA polymerase and Nb.bpu10I endonuclease, a large number of single-stranded DNA (ssDNA) is produced, which induces the opening of a hairpin probe and the subsequent self-assembly to form a hexagonal structure. The staining of the DNA hexagon with SYBR Green I excites the fluorescence signal, which is used for detection. The aptasensor exhibits a broad linear range from 7 to 7 × 107 CFU/mL, with a detection limit of 1.7 CFU/mL for S. aureus. The sensor shows negligible responses to other bacteria. Moreover, the aptasensor has been applied to detect S. aureus in milk samples, and the results demonstrate the general applicability of the sensor and its prospect in systematic detection of S. aureus in food safety control and medicine-related fields. |
| Databáze: | OpenAIRE |
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