A novel fluorescent nanoprobe that based on poly(thymine) single strand DNA-templated copper nanocluster for the detection of hydrogen peroxide

In this paper, a label-free fluorescence nanoprobe is constructed based on poly(thymine) single strand DNA-templated Copper nanocluster (denote as: T-CuNCs) for the detection of hydrogen peroxide. In the assay, the fluorescent T-CuNCs will generate though the reaction of Cu 2+ , poly(thymine) and sodium ascorbate . However, the hydroxyl radical ( . OH) will generated in the presence of H 2 O 2 , which is able to induced the oxidative lesions of poly(thymine) single chain DNA and lead to the poly(thymine) being splitted into shorter or single oligonucleotide fragments and lose the ability to template the fluorescent T-CuNCs again. Therefore, H 2 O 2 can be detected by monitoring the fluorescence strength change of T-CuNCs. The experimental results show that the fluorescence intensity change of T-CuNCs has fantastic linearity versus H 2 O 2 concentration in the range of 1–30 μM (R 2  = 0.9947) and 30–80 μM (R 2  = 0.9972) with the limit of detection (LOD) as low as 0.5 μM (S/N = 3). More important, the fluorescent nanoprobe was also successfully utilized on the detection of H 2 O 2 in serum samples. Therefore, a label-free, costless and effective fluorescence method has been established for the detection of H 2 O 2 , the intrinsic properties of the nanoprobe endow its more potential applications in chemical and biological study.