Label-free impedimetric miRNA-192 genosensor platform using graphene oxide decorated peptide nanotubes composite

•A label-free, sensitive electrochemical assay was developed for miRNA-192 detection.•The biosensor was based on PNT-GO modified PGE with enzyme-free signal transduction.•Self-assembled PNTs and GO nanocomposite was prepared in a simple way.•This is the first study which could detect low levels of miRNA-192 with LOD of 8 fM.•PNT-GO modified PGE was capable of detecting miRNA-192 in peripheral serum samples.