Carbon dots based FRET for the detection of DNA damage

作者：Kudr Jiri; Richtera Lukas; Xhaxhiu Kledi; Hynek David; Heger Zbynek; Zitka Ondrej; Adam Vojtech^*

来源：Biosensors and Bioelectronics, 2017, 92: 133-139.

DOI：10.1016/j.bios.2017.01.067

• Biosensing
• Fluorescence resonance energy transfer
• Quantum dots
• UV irradiation

Here, we aimed our attention at the synthesis of carbon dots (C-dots) with the ability to interact with DNA to suggest an approach for the detection of DNA damage. Primarily, C-dots modified with amine moieties were synthesized using the one-step microwave pyrolysis of citric acid in the presence of diethylenetriamine. The C-dots showed strong photoluminescence with a quantum yield of 4%. In addition, the C-dots (2.8 +/- 0.8 nm) possessed a good colloidal stability and exhibited a positive surface charge (zeta=36 mV) at a neutral pH. An interaction study of the C-dots and the DNA fragment of lambda bacteriophage was performed, and the DNA binding resulted in changes to the photoluminescent and absorption properties of the C-dots. A binding of the C-dots to DNA was also observed as a change to DNA electrophoretic mobility and a decreased ability to intercalate ethidium bromide (EtBr). Moreover, the Forster (or fluorescence) resonance energy transfer (FRET) between the C-dots and EtBr was studied, in which the C-dots serve as an excitation energy donor and the EtBr serves as an acceptor. When DNA was damaged using ultraviolet (UV) radiation (lambda=254 nm) and hydroxyl radicals, the intensity of the emitted photoluminescence at 612 nm significantly decreased. The concept was proved on analysis of the genomic DNA from PC-3 cells and DNA isolated from melanoma tissues.

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