A novel DNA binding protein-based platform for electrochemical detection of miRNA

We present a novel amplification-free sandwich type platform assay for electrochemical detection of miRNA. The assay is based on T4 DNA polymerase mediated synthesis of the p53 binding DNA sequence at the 3 ' end of target miRNA. The resulting miRNA-DNA chimera is detected via an electrochemical sandwich hybridization assay where HRP-labelled p53 binds to its recognition sequence and an amperometric signal is generated by hydroquinone-mediated enzymatic reduction of H2O2. The limit of detection of our assay was estimated to be 22 fM with a linear dynamic range of 100 fM-1 nM. This new platform method of detecting miRNA shows superior performance to conventional electrochemical miRNA biosensors and has the potential for amplification-free analysis of miRNA with high specificity and sensitivity.

Automated summary

The novel amplification-free sandwich type platform assay presented in this study utilizes T4 DNA polymerase to synthesize miRNA-DNA chimera for electrochemical detection, with a detection limit estimated to be 22 fM and a linear dynamic range of 100 fM-1 nM. This new platform method shows superior performance to conventional electrochemical miRNA biosensors and has the potential for amplification-free analysis of miRNA with high specificity and sensitivity.