Gold nanoparticles (AuNPs) have a numerous biomedical applications including their antioxidant, antimicrobial, and anticancer applications. We have synthesized AuNPs laced with the extracts of red algae Halymenia pseudofloresii using the green method (Hp-AuNPs). The synthesized nanoparticles were characterized by UV spectroscopy, XRD, FTIR, and SEM. In UV spectroscopy, Hp-AuNP’s surface plasmon resonance (SPR) peak was discovered to be at 545 nm, which initially confirmed the formation of nanoparticles. The X-ray diffraction analysis confirmed the biosynthesized Hp-AuNP structures to be crystal in nature. Bioactive molecules, such as phenolic compounds and carboxylic groups, were identified by FTIR analysis as contributing to the reduction of Hp-AuNPs. The scanning electron microscope (SEM) analysis was used to identify the Hp-AuNP morphology as cubic and rectangular structures with 27 nm size. The antioxidant activity demonstrated that H. pseudofloresii extract (61.3%) and synthesized Hp-AuNPs (71.87%) effectively inhibited the DPPH radicals at 50 µg/mL concentration. The Hp-AuNPs exhibited efficient antibacterial effects against Staphylococcus aureus (24 mm), Lactobacillus (23 mm), and Pseudomonas aeruginosa (22 mm). The biosynthesized Hp-AuNPs showed potential cytotoxic activity against A549 lung cancer (IC₅₀ = 19.02 µg/mL) than LN-18 glioblastoma cancer cells (IC₅₀ = 32.46 µg/mL). Hence, further anticancer screening was tested against lung cancer cells. In the clonogenic assay, Hp-AuNPs effectively control the lung cancer cell colony formation at the concentration of 30 µg/mL, whereas the Hp-AuNPs induce apoptotic activity in lung cancer cells was confirmed through reactive oxygen species (ROS) generation assay. Therefore, the unique biologically synthesized Hp-AuNPs have the ability to function as an anticancer agent, and they may further be used for a variety of biomedical purposes.

金纳米粒子 (AuNP) 具有多种生物医学应用，包括抗氧化、抗菌和抗癌应用。我们合成了含有红藻Halymenia pseudofloresii提取物的 AuNP使用绿色方法 (Hp-AuNPs)。通过紫外光谱、XRD、FTIR 和 SEM 对合成的纳米粒子进行了表征。在紫外光谱中，发现 Hp-AuNP 的表面等离子体共振 (SPR) 峰位于 545 nm，这初步证实了纳米粒子的形成。X 射线衍射分析证实生物合成的 Hp-AuNP 结构本质上是晶体。生物活性分子，如酚类化合物和羧基，通过 FTIR 分析确定有助于减少 Hp-AuNP。扫描电子显微镜 (SEM) 分析用于将 Hp-AuNP 形态识别为具有 27 nm 尺寸的立方体和矩形结构。抗氧化活性表明H. pseudofloresii提取物 (61.3%) 和合成的 Hp-AuNPs (71.87%) 在 50 µg/mL 浓度下有效抑制 DPPH 自由基。Hp-AuNPs 对金黄色葡萄球菌(24 mm)、乳酸杆菌(23 mm) 和铜绿假单胞菌(22 mm) 表现出有效的抗菌作用。生物合成的 Hp-AuNPs比 LN-18 胶质_母 细胞瘤癌细胞 (IC ₅₀ = 32.46 微克/毫升）。因此，针对肺癌细胞进行了进一步的抗癌筛查。在克隆形成试验中，Hp-AuNPs 在 30 µg/mL 的浓度下有效控制肺癌细胞集落形成，而 Hp-AuNPs 在肺癌细胞中诱导凋亡活性通过活性氧 (ROS) 生成试验得到证实。因此，独特的生物合成的 Hp-AuNPs 具有抗癌剂的功能，可进一步用于多种生物医学目的。