Measurement of microRNA-106b as a gastric cancer biomarker based on Zn-BTC MOF label-free genosensor

Due to the late detection of stomach cancer, this cancer usually causes high mortality. The development of an electrochemical genosensor to measure microRNA 106b (miR-106b), as a gastric cancer biomarker, is the aim of this effort. In this regard, first, 1,3,5-benzenetricarboxylate (BTC) metal-organic frameworks (Zn-BTC MOF) were self-assembled on the glassy carbon electrode and then the probe (ssDNA) was immobilized on it. The morphology Zn-BTC MOF was characterized by SEM, FT-IR, Raman and X-Ray techniques. Zn-BTC MOF as a biosensor substrate has strong interaction with ssDNA. Quantitative measurement of miR-106b was performed by electrochemical impedance spectroscopy (EIS). To perform this measurement, the difference of the charge transfer resistances (ΔRct) of Nyquist plots of the ssDNA probe modified electrode before and after hybridization with miR-106b was obtained and used as an analytical signal. Using the suggested genosensor, it is possible to measure miR-106b in the concentration range of 1.0 fM to 1.0 μM with a detection limit of 0.65 fM under optimal conditions. Moreover, at the genosensor surface, miR-106b can be detected from a non-complementary and a single base mismatch sequence. Also, the genosensor was used to assess miR-106b in a human serum sample and obtained satisfactory results. [Display omitted] •MiR-106b is one of the miRNAs that is significantly increased in gastric cancer patients.•A label-free electrochemical genosensor is developed to measure miR-106b.•Using the genosensor, the miR-106b concentration was measured in the range of 1.0 fM to 1.0 μM.•A detection limit of 0.65 fM was obtained for the measurement of miR-106b.•At the genosensor surface, miR-106 can be detected from a single base mismatch sequence.•Using the genosensor, miR-106b can be measured in human serum samples.•Zn-BTC MOF act as a base for ss-DNA assembly and enhances the signal.