Nucleotide biosensor for detection and differentiation of miRNA 181a by electrochemical technique

MicroRNAs (miRNA) are crucial regulators of a wide range of cellular processes and have been identified as promising different diseases biomarkers such as cancer due to their stable presence in serum. MicroRNA181a has significant role in life ration, and metastasis in several kinds of syndromes and cancers. In this work the electrochemical DNA biosensor is presented based on glassy carbon electrode (GCE) for immobilization and detection of short MicroRNA sequences with methylene blue (MB) as electroactive label within conducting polymer polypyrrole (Ppy). Any variation in the MB signal represents the extent of hybridization at the electrode surface. The interaction of MB with DNA is electrochemically detected and MB displayed different signals in the states of interacted with ssDNA and dsDNA. The pH effects on the electrochemical behavior of MB signals, the effect of electrochemical pretreatment of GCE on the ability of electrode in probe adsorption, MB accumulation and conditions of probe immobilization including potential and time were comprehensively investigated. We found that the peaks of current are related to the concentration of the target oligonucleotide sequence. Data were achieved using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods

Keywords:

Microrna , Mir-181a , Electropolymerization , Pyrrole , Methylene Blue , Cyclic Voltammetry , Differential Pulse Voltammetry