Synthesis of a novel fluorescent probe useful for DNA detection.

In this paper, a novel fluorescent probe 2-methylbenzo[b][1,10] phenanthrolin-7(12H)-one (m-BPO) is synthesized, and its molecular structure has been characterized by IR, UV, MS, (1)H-NMR and elements analysis. The fluorescent characteristics of m-BPO were investigated in detail. It was found that DNA had the ability to quench the fluorescence of m-BPO at 411 nm (lambda(ex)=286 nm), and the quenched intensity of fluorescence was proportional to the concentration of DNA. Based on this fact, m-BPO has been used as the fluorescent probe for detection of calf thymus DNA (ctDNA) and fish semen DNA (fsDNA). Under the optimal conditions, the calibration curves are linear up to 15.0 microg/ml for both ctDNA and fsDNA. The corresponding detection limits are 3.6 ng/ml for ctDNA and 5.5 ng/ml for fsDNA, respectively. The interaction mechanism for the binding of m-BPO to ctDNA was studied in detail, and the results suggested that the interaction mode between m-BPO and ctDNA was groove binding.