A Sensitive and Selective Electrochemical Biosensor for Detection of MicroRNA-181a as a Very Critical Biomarker for Detection of Some Cancers

A Sensitive and Selective Electrochemical Biosensor for Detection of MicroRNA-181a as a Very Critical Biomarker for Detection of Some Cancers
Alireza Soleimanian,^1,* Parivar Yazdani,² Zakiyeh Nikipar,³ Vahideh Tarhriz,⁴
1. Department of Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran.
2. Molecular Medicine Research Center, Biomedicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran
3. Molecular Medicine Research Center, Biomedicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran
4. Molecular Medicine Research Center, Biomedicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran
Introduction: MicroRNAs (miRNA) are short, noncoding, single strand RNAs and they have very vital roles in proliferation, apoptosis, differentiation and gene silencing. This kind of RNAs can use as cancer biomarker. mir181a, a kind of miRNA, is a biomarker to detection of some cancers such as gastric cancer, colorectal cancer, breast cancer metastasis, epithelial ovarian cancer (EOC), hepatocellular carcinoma (HCC) and acute myeloid leukemia (AML). Dysregulation of mir181a is an important marker for mentioned cancers. Therefore, analyzing of this biomarker is very useful for clinicians, because they can detect some cancers (as mentioned above) in the early stage.
Methods: Biosensors are very useful and very sensitive devices and researches use it medicine for detection of diseases, for example cancer. Detection of cancer in the early stage is vital because curing of cancer in early stage is simple. In this regard, we developed an electrochemical DNA based biosensor for detection and capturing of miRNA181a. For this aim, we used polypyrrole (PPy) and antimiRNA-181a probes (were used as target (miRNA-181a) capturing element) on glassy carbon electrode (GCE) and methylene blue (MB) as electroactive label in electrochemical analyze.
Results: In this research, electrochemical techniques (CV, DPV), AFM and FTIR spectrophotometric techniques were used for modification of electrode and approving of biosensor preparation steps. After passing the optimization of all experimental parameters, the modified electrode after an overnight duration analyzed by DPV technique and stability of it confirmed. Selectivity of biosensor verified by DVP technique by using of non-complementary microRNAs (designed biosensor connected only to target microRNAs) and sensitivity (3 ppm) of the designed biosensor for target microRNA analyzed by electrochemical techniques.
Conclusion: The designed biosensor in this research is very sensitive, selective, inexpensive, repeatable and has fast response time. Therefore, this biosensor can detect very low concentration of miRNA-181a. Therefore, it is a very useful analytical device for early detection of cancers in clinical laboratories and help to clinicians to treatment of patients.
Keywords: Cancer, Electrochemical Biosensor, Biomedical Analysis, MicroRNA-181a