Nano-selenium was synthesized using lemon juice as a reducing agent. The experiments showed that pH value affected greatly the shape and the size of the prepared nano-selenium. At pH 9, lemon juice could reduce 50 mmol/L of selenite ions to nano-selenium with particle size between 50 and 90 nm, which was spherical and well dispersed. Lemon juice acted as both a reducing agent and a stabilizer in the synthesis of nano-selenium, in which the chemical interaction between biomolecules and the nano-selenium surface was the basis for the stable existence of nano-selenium. The selenite concentration influenced the formation of nano-selenium, and a low selenite concentration was beneficial to obtain small particles. The achieved nano-selenium exhibited a strong antioxidant activity positively related to concentration. The comparative study showed that the antioxidation of nano-selenium is weaker than that of vitamin C but higher than that of lemon juice. Graphical abstract Green synthesis of nano-selenium from lemon juice, selenium nanoparticles coated with macromolecules, and antioxidant activity.

中文翻译：

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以柠檬汁为还原剂的纳米硒的生物合成与抗氧化

使用柠檬汁作为还原剂合成了纳米硒。实验表明，pH值对制备的纳米硒的形状和大小有很大影响。在pH 9时，柠檬汁可以将50 mmol / L的亚硒离子还原为粒径为50至90 nm的纳米硒，其球形且分散良好。柠檬汁在纳米硒的合成中既是还原剂又是稳定剂，其中生物分子与纳米硒表面之间的化学相互作用是纳米硒稳定存在的基础。亚硒酸盐的浓度影响了纳米硒的形成，低亚硒酸盐的浓度有利于获得小颗粒。所获得的纳米硒表现出与浓度成正比的强抗氧化活性。对比研究表明，纳米硒的抗氧化能力比维生素C弱，但高于柠檬汁。图形摘要由柠檬汁，包覆有大分子的硒纳米颗粒和抗氧化活性绿色合成纳米硒。