Abstract Carbon dots (CDs) have been widely applied in bioimaging, drug delivery and nanomedicine. In this study, the interaction binding mechanism of CDs with calf thymus DNA (ctDNA) has been investigated. A bottom-up synthetic route was selected at low temperature and a one-pot green synthesis of CDs was applied with ascorbic acid as carbon precursor and a water phase reflow at 90 °C under stirring for 3.5 h. The resulting as-synthesized CDs exhibited a green-yellow color, different than what has already been reported for this product with ascorbic acid as carbon precursor. The quantum yield of CDs was 13.3% and the fluorescence decay was 3.19 ns. Analytic methods such as UV-vis absorbance, fluorescence spectroscopy, circular dichroism spectroscopy and electrochemical approaches were used to study the binding mechanism between the CDs and ctDNA. Overall, the results indicated that the binding mode between CDs and ctDNA was intercalation. Moreover, the CDs exhibited specific properties that may be useful in the replacement of other, often toxic fluorescent dyes that are commonly used for organ imaging. CDs may therefore represent a promising fluorescence probe of ctDNA.

中文翻译：

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探索碳点与小牛胸腺 DNA 的结合：从绿色合成到荧光分子探针

摘要 碳点（CDs）已广泛应用于生物成像、药物输送和纳米医学领域。在这项研究中，研究了 CD 与小牛胸腺 DNA (ctDNA) 的相互作用结合机制。选择低温自下而上的合成路线，以抗坏血酸为碳前驱体，在90°C下搅拌3.5小时水相回流，进行CDs的一锅绿色合成。合成后的 CD 呈现绿黄色，与已经报道的这种以抗坏血酸作为碳前体的产品不同。CDs的量子产率为13.3%，荧光衰减为3.19 ns。使用紫外-可见吸光度、荧光光谱、圆二色光谱和电化学方法等分析方法研究了 CD 与 ctDNA 之间的结合机制。总的来说，结果表明CDs和ctDNA之间的结合模式是嵌入。此外，CDs 表现出特定的特性，可用于替代通常用于器官成像的其他通常有毒的荧光染料。因此，CD 可能是一种很有前景的 ctDNA 荧光探针。