Design of fluorescence nano biosensor for early detection of colorectal cancer using APC probe in the presence of MWCNT

APC gene in ctDNA has been proposed as a potential biomarker for cancer diagnosis. A biosensor based on a multi-walled carbon nanotube (MWCNT) and DNA probe with fluorophore FAM (6-carboxyfluorescein) for detection of APC gene in ctDNA was developed to identify patients with colorectal cancer (CRC).This method was designed based on the adsorption and immobilization of FAM-labeled single-stranded DNA (ssDNA) on MWCNT, which leads to the quenching of FAM fluorescence emission. By adding its cDNA could release single-stranded DNA probe (ssDNA) from the MWCNT surface and a double-stranded DNA (dsDNA) was formed. It led to the return of FAM fluorescence emission. While in the case of non-complementary DNA the corresponding dsDNA was not formed and therefore we did not have the return of FAM fluorescence emission. The results of this study showed that the biosensor based on carbon nanotubes can be used as a high-sensitivity method for the early detection of CRC.