Graphene quantum dots (GQDs) are known as emerging sub‐10 nm nanoparticles (NPs), which are in fact few‐layered pieces of graphene, capable of emitting blue fluorescence, when exposed to 360 nm UV light. Understanding the details of the interaction between GQDs and lipase can serve as a critical step for improving the biological outcome of GQD‐derived drug‐delivery and diagnosis systems. The interaction occurs in the form of surface adsorption, which can subsequently influence the physicochemical properties of both the NP and the protein. Hence, a systematic approach was taken here to optimize the GQDs' synthesis conditions in order to achieve the highest possible quantum yield (QY). Furthermore, to understands the influence of the interaction of GQDs and lipase, on both the activity of lipase and the emission intensity of GQDs, various incubation conditions were tested to achieve optimized conditions over central composite design algorithm by Design‐Expert®, using response surface methodology. The results show that the GQDs fabricated by thermal decomposition of citric acid at 160°C, with a heating duration of 55 min, obtain almost three times higher QY than the highest values reported previously. The best enzymatic activity after the formation of the hard corona, as well as the highest fluorescent emission, were achieved at GQD‐to‐enzyme ratios within the rage of 23–25%, at temperatures between 41 and 42°C, for 6–8 min. In the aforementioned condition, the enzyme retains 91–95% of its activity and the NP preserves about 80–82% of its fluorescence intensity after incubation.

中文翻译：

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优化石墨烯量子点与脂肪酶在生物应用中的相互作用。

石墨烯量子点 (GQDs) 被称为新兴的亚 10 nm 纳米粒子 (NPs)，它们实际上是几层石墨烯片，当暴露于 360 nm 紫外线时能够发出蓝色荧光。了解 GQD 和脂肪酶之间相互作用的细节可以作为改善 GQD 衍生的药物递送和诊断系统的生物学结果的关键步骤。相互作用以表面吸附的形式发生，随后会影响 NP 和蛋白质的理化性质。因此，这里采用系统方法来优化 GQD 的合成条件，以实现最高可能的量子产率 (QY)。此外，为了了解 GQDs 和脂肪酶的相互作用对脂肪酶活性和 GQDs 发射强度的影响，Design-Expert® 使用响应面方法测试了各种孵化条件，以实现中心复合设计算法的优化条件。结果表明，通过柠檬酸在 160°C 下热分解制备的 GQD，加热时间为 55 分钟，获得的 QY 几乎是之前报道的最高值的三倍。硬电晕形成后的最佳酶活性以及最高的荧光发射是在 GQD 与酶比在 23-25% 范围内、温度在 41 至 42°C 之间进行 6-6- 8 分钟 在上述条件下，酶在孵育后保留了 91-95% 的活性，NP 保留了约 80-82% 的荧光强度。