Farima Dehghan - Department of biological science, Genetics, Ashkezar Branch, Islamic Azad University, Yazd, Iran
Navid Nasirizadeh - Department of Textile and Polymer Engineering, Yazd Branch, Islamic Azad University, Yazd, Iran
Seyed Morteza Seifati - Scientific Society of Nanotechnology, Yazd Branch, Islamic Azad University, Yazd, Iran

Abstract:For the detection of DNA hybridization, a new electrochemical biosensor was developed on the basis of the interaction of Oracet Blue (OB) with 22-mer oligonucleotides (from human Colorectal cancer) a simple biosensing design to yield an ultrasensitive electrochemical biosensor for cancer biomarker detection on Screen Printed Gold Electrodes (SPGE) without use of any modification on electrode surface perhaps direct detection with the help of electroactive label (OB) and MicroRNA92a (miRNA) as an biomarker selected for being up-regulated in Colorectal cancer. The biosensor was assembled in two stages the immobilization of the probe that was modified on an SPGE and second stage of target hybridization of completely match strand electroactive label OB has been used after hybridization process which is an intercalator with our miRNA strands as an redox indicator for amplifying the electrochemical signal of miRNA 92a. For conformation electrochemical techniques including Cyclic Voltammetery (CV) and Differential Pulse Voltammetery (DPV). were used and hybridization was observed successfully .The final biosensor provided a sensitive detection of miRNA 92a with good selectivity.

miRNA92a, Colorectal Cancer, Electrochemical biosensor