Efficient pharmacotherapy of cancer is related to accurate recognition of genetic mutations and epigenetic alterations in the early-stage diagnosis. In the present study, a novel optical genosensor based on toluidine blue as photonic probe was developed to detection of DNA methylation using hybridization of pDNA with cDNA. Biomedical analysis was performed using UV-vis and fluorometric methods. For the first time, this strategy was applied for the distinction of methylated DNA from unmethylated-DNA-based on the interaction of optical probe with methylated-DNA and unmethylated DNA. Fluorescence spectroscopic data showed that poly-toluidine blue could be bind to DNA sequences and lead to different fluorescence patterns and could be used as an efficient geno-platform for the sensitive bioassay of mutation. The excitation and emission wavelengths were 580 and 630 nm, respectively. Non-binding of mismatch sequences with the optical probe was used as negative control. Under optimal conditions, linear range was 1zM to 0.2 pm and the lower limit of quantitation was obtained as target concentrations ranging 1zM. The designed genosensor showed high capability to distinct methylation from un-methylated. Therefore, the designed DNA-based bioassay could detect DNA methylation significantly. Finally, bioanalysis of real samples showed that the designed genosensor could use to detect DNA methylation which is a new platform for point of care analysis.