Aptamer-based colorimetric detection of methicillin-resistant Staphylococcus aureus by using a CRISPR/Cas12a system and recombinase polymerase amplification br

作者：Wei, Luyu; Wang, Zhilong; Wang, Jia; Wang, Xiaohong; Chen, Yiping^*

来源：Analytica Chimica Acta, 2022, 1230: 340357.

DOI：10.1016/j.aca.2022.340357

• CRISPR
• Cas12a
• Methicillin-resistant Staphylococcus aureus
• Colorimetric analysis
• Aptamer
• Ag plus -TMB system

Detection of methicillin-resistant Staphylococcus aureus (MRSA) with superior accuracy, timeliness, and simplicity is highly valuable in clinical diagnosis and food safety. In this study, an aptamer-based colorimetric biosensor was developed to detect MRSA by using a CRISPR/Cas12a system and recombinase polymerase amplification (RPA). The aptamer of silver ion (Ag+) pre-coupled to magnetic nanoparticles was employed not only as the substrate of trans-cleavage in the CRISPR/Cas12a system, but also as the modulator of Ag+-3,3 ',5,5 ' tetramethylbenzidine (TMB) chromogenic reaction, innovatively integrating the powerful CRISPR/Cas12a system with convenient colorimetry. The utilized aptamer containing consecutive and interrupted cytosine: cytosine mismatched base pairs also served as a signal amplifier because of the one-to-multiple binding of the aptamer to Ag+. Using triple amplification of RPA, multiple-turnover nuclease activity of Cas12a, and cytosine-Ag+-cytosine coordination chemistry, MRSA was detected as low as 8 CFU mL-1. Moreover, its satisfactory accuracy in the analysis of real samples, together with visualization and simplicity, revealed the great potential of the proposed biosensor as a robust antibiotic-resistant bacteria detection platform.

• 单位
  华中农业大学