Hemoglobin assisted carbon nanofiber preparation for selective detection of miRNA molecules

A selective miRNA detection is an important factor for the early-stage diagnosis of the diseases and determination of an appropriate treatment method. In this regard, hemoglobin assisted carbon nanofibers (CNFs) were prepared via electrospinning of the precursor polyacrylonitrile/hemoglobin (PAN/Hb) hybrid nanofibers and the following heat treatment process. Addition of low ratio Hb in the precursor PAN nanofibers caused a catalytic effect on the reaction taken place during the stabilization process that helps the formation of more graphitic structure during the carbonization process. But, increasing Hb ratio in the PAN/Hb nanofibers caused an inhibiting effect on the related reactions. Guanine oxidation signals of miRNA molecules were determined via differential pulse voltammetry (DPV) measurement. In this regard, the attachment of anti-miRNA molecules on the CNFs immobilized screen-printed electrodes (SPEs) and a following hybridization of the attached anti-miRNA with miRNA molecules were carried out. Three different miRNA molecules including the target (miRNA), single-base mismatched (SM.miRNA), and non-complementary (NC.miRNA) were hybridized with the previously attached anti-miRNA molecules on the Hb-CNFs immobilized SPEs. The enhancement of the guanine oxidation signal level was observed by using Hb-CNFs instead of using CNFs. That could be attributed to the increase of the graphitic level with low Hb addition to the precursor PAN/Hb nanofibers that causes a catalytic effect on carbonization process. The prepared biosensory system could be used for the selective detection of miRNA molecules.