Cyclobutane pyrimidine dimmers (CPDs) and 6-4-[pyrimidine-2'-one] pyrimidine (6-4 PP) are major UV induced DNA damage lesions formed from solar radiation and other sources. CPD lesions are presumably mutagenic and carcinogenic that inhibit polymerases and interfere in DNA replication. An easy and cost effective way for visual detection of these lesions by using fluorescence based method is shown here. Artificial UVA and UVB lights were used for the generation of CPD and 6-4 PPs in selected DNA samples. Binding of Hg2+ ions with DNA before and after induction of CPD and 6-4 PP lesions was evaluated in the presence of highly fluorescent blue emitting carbon dots (CDs). Induction of CPD and 6-4 PPs in DNA causes distortion of DNA structure which hinders the binding of Hg2+ ions to DNA nucleobases. Quenching of fluorescence intensity of CDs by unbound Hg2+ ions was found to be proportional to the amount of CPD and 6-4 PP lesions induced by UV irradiation of DNA samples that offer a biosensing platform for the sensitive detection of CPD lesions in DNA. The fluorescent quenching was visually detectable using hand held UV light without the intervention of any equipment.

中文翻译：

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Hg 2+ 和碳点对环丁烷嘧啶二聚体 DNA 损伤病变的视觉检测

环丁烷嘧啶二聚体 (CPD) 和 6-4-[pyrimidine-2'-one] 嘧啶 (6-4 PP) 是由太阳辐射和其他来源形成的主要紫外线诱导 DNA 损伤病变。CPD 病变可能具有致突变性和致癌性，可抑制聚合酶并干扰 DNA 复制。此处显示了一种使用基于荧光的方法对这些病变进行视觉检测的简单且经济有效的方法。人工 UVA 和 UVB 灯用于在选定的 DNA 样品中生成 CPD 和 6-4 PP。在存在高荧光蓝色发射碳点 (CD) 的情况下，评估了 CPD 和 6-4 PP 病变诱导前后 Hg2+ 离子与 DNA 的结合。DNA 中 CPD 和 6-4 PP 的诱导会导致 DNA 结构的扭曲，从而阻碍 Hg2+ 离子与 DNA 核碱基的结合。发现未结合的 Hg2+ 离子对 CD 荧光强度的淬灭与 DNA 样品的紫外线照射引起的 CPD 和 6-4 PP 损伤的数量成正比，这为 DNA 中 CPD 损伤的灵敏检测提供了生物传感平台。荧光猝灭可使用手持式紫外灯目测检测，无需任何设备干预。