fabrication of an electrochemical biosensor for early detection of colorectal cancer based on mirna hybridyzation method

for the detection of dna hybridization, a new electrochemical biosensor was developed on the basis of the interaction of doxirubicine (dox) 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 (dox) 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 dox 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.