Impedimetric monitoring of microRNA-200c-3p using hydroxyapatite nanoparticles modified pencil graphite electrodes

Abstract

It is important to monitor miRNA-200c-3p as it can potentially serve as an important biomarker for respiratory diseases including COVID-19 and cancer. Despite the importance of microRNA monitoring, there are few previous studies for miRNA-200c-3p monitoring, and the application of hydroxyapatite nanoparticles (HaNP) in miRNA biosensors is quite limited. This study aims to fill this gap by utilizing the advantageous properties of HaNPs to develop a powerful strategy to detect microRNA-200c-3p. First, HaNPs were modified on the surface of pencil graphite electrodes (PGEs). Subsequently, hybridization between a phosphate-labeled miRNA-200c-3p-specific DNA probe and its complementary RNA target was carried out in the solution phase. The DNA-RNA hybrid forms were immobilized on the surface of the HaNP-PGEs and the impedimetric measurements were performed. The changes at the charge transfer resistance value (Rct) were evaluated in terms of the hybridization and optimization of the experimental conditions. The detection limits (DLs) were calculated as 0.12 µg/mL (16.19 nM) in phosphate buffer solution (PBS, pH 7.40) and 0.31 µg/mL (41.82 nM) in synthetic plasma. The selectivity of the developed biosensor was tested against miRNA-200c-5p and miRNA-141-3p. The results promise a significant improvement in public health in terms of a leap forward in the early diagnosis of many serious diseases.