Simultaneous detection of ovarian cancer related miRNA biomarkers with carboxylated graphene oxide modified electrochemical biosensor platform

Ovarian cancer, known as "silent killer", is a gynocological cancer with high mortality that usually diagnosed in the late stages. Gold standard immunoassay technique is evaluation of CA-125 levels which is not merely specific to ovarian cancer. Therefore, there is a need for sensitive determination of more specific biomarkers. miR-200 family is RNA nucleic acids that known to be upregulated in the presence of ovarian cancer. Since diagnosis based on a single biomarker is prone to generate misleading results, it is important to develop point-of-care systems that allow diagnosis of multiple miRNAs. Herein, an electrochemical nanobiosensor platform was developed for the multiplexed and simultaneous detection of miR-200c and miR-141. Biorecognition part was constitutued of methylene blue and ferrocene labeled hairpin DNA probes immobilized onto carboxylated graphene oxide modified pencil graphite electrodes. Their hybridization with miRNAs were examined upon "signal-off" approach using Square Wave Voltammetry. The platform demonstrated a linear detection range of 0.1 pM to 10 nM for both miR-141 and miR-200c, with low detection limits of 0.029 pM and 0.026 pM, respectively. We assume that the developed biosensor platform may pave the way in early diagnosis of the disease and the development of more effective treatment strategies.