An innovative fluorometric bioanalysis strategy towards recognition of DNA methylation using opto-active polymer: A new platform for DNA damage studies by genosensor technology.

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 1 zM to 0.2 pm and the lower limit of quantitation was obtained as target concentrations ranging 1 zM. 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.