RESUMO
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 Cu2+, poly(thymine) and sodium ascorbate. However, the hydroxyl radical (.OH) will generated in the presence of H2O2, 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, H2O2 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 H2O2 concentration in the range of 1-30 µM (R2 = 0.9947) and 30-80 µM (R2 = 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 H2O2 in serum samples. Therefore, a label-free, costless and effective fluorescence method has been established for the detection of H2O2, the intrinsic properties of the nanoprobe endow its more potential applications in chemical and biological study.