Amplified electrochemical detection of mecA gene in methicillin-resistant Staphylococcus aureus based on target recycling amplification and isothermal strand-displacement polymerization reaction

作者：Wang Ting; Zhang Zhang; Li Yiyan; Xie Guoming

来源：Sensors and Actuators B: Chemical , 2015, 221: 148-154.

DOI：10.1016/j.snb.2015.06.057

• Methicillin-resistant Staphylococcus aureus
• mecA gene
• Target recycling
• Strand displacement
• Polymerization reaction
• Electrochemical DNA sensor

Rapid detection of drug-resistant bacteria can facilitate the early diagnosis of various infections and provide essential guidance for appropriate usage of antibiotics. An ultrasensitive electrochemical DNA (E-DNA) sensor based on isothermal strand-displacement polymerization reaction (ISDPR) for detection of mecA gene in methicillin-resistant Staphylococcus aureus (MRSA) was proposed in this study. Methylene blue (MB)-labeled hairpin probes were self-assembled on a gold electrode to confine MB molecules close to the electrode surface for efficient electron transfer. The hairpin probes were then hybridized with complementary target DNA and undergone conformational changes, which led to a decreased electrochemical response. The primers annealed with the opened stems of hairpin probes were extended by DNA polymerase, which in turn released the target DNA to trigger the next polymerization cycle. Finally, each target DNA underwent through many rounds, resulting in a mass of MB molecules moved away from the electrode surface, which generated significant amplified current suppression for mecA gene detection. With this target recycling amplification strategy, the proposed DNA biosensor could offer excellent analytical performance for the detection of mecA gene and provide a new electrochemical method for the early diagnosis of drug-resistant bacteria.

• 出版日期2015-12-31
• 单位重庆医科大学