Endonuclease cleavage combined with horseradish peroxidase-assisted signal amplification for electrochemical monitoring of DNA

A novel and universal electrochemical strategy for monitoring DNA was developed based on specific cleavage of MspI endonuclease combining with streptavidin-horseradish peroxidase (SA-HRP) conjugate. By introducing the strategy to mycobacterium tuberculosis (MTB) DNA detection, the probe DNA was immobilized on Au electrode via AuS bond and SA-HRP conjugate was linked to probe DNA by biotin-SA specific interaction, which led to the first application in MTB DNA electrochemical detection. This proposed electrochemical method exhibited satisfactory performance which could detect MTB DNA linearly ranging from 10 pM to 100 nM with a detection limit of 2.3 pM. The novel strategy of DNA analysis showed a promising application in clinic diagnostics.