In recent years, researches on selenium nanoparticle have gained more attention due to its important role in many physiological processes. Generally, selenium nanoparticle has a high level of absorption in regular supplementation comparative to selenium. Therefore it is all-important to develop new techniques to elevate the transportation of selenium compounds (selenoproteins, selenoenzymes, etc.) by increasing their bioavailability, bioactivity, and controlled release. SeNPs have special attention regarding their application as food additives and therapeutic agents. Selenium nanoparticle has biomedical and pharmaceutical uses due to its antioxidant, antimicrobial, antidiabetic, and anticancer effects. Selenium nanoparticle is also used to antagonize the toxic effect of chemical and heavy metals. SeNPs are beneficial for the treatment of water and soil contaminated with metals and heavy metals as it has adsorption capability. Selenium nanoparticle is synthesized by the bioreduction of selenium species (sodium selenate, sodium selenite, selenium dioxide, and selenium tetrachloride, etc.) by using bacteria, fungi, plant, and plant extracts, which have given hope for the bioremediation of selenium contaminated water and soils. This article reviews the procedure of selenium nanoparticle synthesis (physical, chemical and biological methods), characterization (UV- visible spectroscopy, transmission electron microscopy, Scanning electron microscopy, electron dispersive X-ray spectroscopy, X-ray diffraction, Fourier transform-infrared spectroscopy, etc.), with the emphasis on its role and application in health and environment.

近年来，硒纳米颗粒的研究因其在许多生理过程中的重要作用而受到越来越多的关注。通常，与硒相比，硒纳米颗粒在定期补充中具有较高的吸收水平。因此，开发新技术以通过增加硒化合物（硒蛋白、硒酶等）的生物利用度、生物活性和控制释放来提高其运输是非常重要的。SeNPs 特别关注它们作为食品添加剂和治疗剂的应用。硒纳米颗粒由于其抗氧化、抗菌、抗糖尿病和抗癌作用而具有生物医学和制药用途。硒纳米颗粒还用于对抗化学和重金属的毒性作用。SeNPs 具有吸附能力，有利于处理被金属和重金属污染的水和土壤。硒纳米颗粒是利用细菌、真菌、植物和植物提取物对硒物种（硒酸钠、亚硒酸钠、二氧化硒和四氯化硒等）进行生物还原合成的，为硒污染水的生物修复带来了希望和土壤。本文综述了硒纳米粒子的合成过程（物理、化学和生物方法）、表征（紫外可见光谱、透射电子显微镜、扫描电子显微镜、电子色散 X 射线光谱、X 射线衍射、傅里叶变换红外光谱）等），强调其在健康和环境中的作用和应用。