辐射包括多种形式，在宇宙中无处不在，它对于人类来说是一种可以利用的资源，但同时也威胁着我们的健康。在这其中，电离辐射是对于生物危害较大的辐射形式，它能够引起多种病变威胁生命。黑色素是自然界中的一种天然辐射防护剂，对于生物体有着非常重要的意义。除了辐射防护之外，黑色素还具有自由基清除、色素沉着、体温调控等多种功能。由于X射线的吸收系数与原子序数（Z）的四次方成正比，因而将黑色素中的硫元素替换为硒元素可以有效的提高其对于辐射的防护能力，同时我们预测减少聚合物分子的羧基侧链可以进一步优化硒黑素的结构，使得其能够展现出更好的辐射防护性能。基于此，我们设计并合成了新型含硒黑色素，利用多种技术对于纳米粒子进行表征，验证了其具有理想的形貌及硒元素含量。同时测试了硒黑素纳米粒子对于活性氧的清除能力，得到了令人满意的结果，证明了新型含硒黑色素具有较高硒含量并且对于活性氧也有较好的清除能力，具有广阔的前景。

Radiation includes various forms and ubiquitous in the universe. It can be utilized as a resource by humans, but also poses a threat to our health. Of all the forms, ionizing radiation is the most harmful to organisms and can cause various pathological changes that can be life-threatening. Melanin is a natural radiation protection agent, which plays a crucial role in protecting organisms from harmful radiation. Apart from its radiation protecting properties, melanin also functions as a free radical scavenger, pigmentation, and thermal regulation. It is worth noting that by replacing sulfur with selenium in melanin, the radiation protection ability can be significantly enhanced, as the absorption coefficient of X-ray is directly proportional to the fourth power of atomic number (Z). We hypothesize that by reducing the carboxyl side chain of macromolecules, the structure of selenium melanin can be further optimized to enhance its radiation protection performance. Based on this, we designed and synthesized a new type of selenomelanin, characterized the nanoparticles using a variety of technologies to verify that it has an ideal morphology and selenium content. At the same time, the scavenging capacity of selenomelanin nanoparticles for reactive oxygen species was tested, satisfactory results were obtained, which proved that the new selenium containing melanin has high selenium content and good scavenging capacity for reactive oxygen species, and has broad prospects.