Abstract In this study, bimetallic nanoparticles comprising silver and platinum with promising therapeutic activities were synthesized using ethanolic Vernonia mespilifolia plant extract for the first time. The bimetallic silver-platinum nanoparticles (AgPtNPs) were characterized using solid-state techniques including UV–vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDX) techniques. The internal morphological structure showed that the AgPtNPs were spherical with a diameter of approximately 35.5 ± 0.8 nm, while FTIR confirmed the effective capping and formation of the nanoparticles by phytoconstituents. The polyphenolic contents of the green synthesized nanoparticles from the ethanolic extract of V. mespilifolia (AgNPs and AgPtNPs) was found to be (28.0 ± 0.8 and 13.6 ± 0.1 mg GAE/g) total phenol, while the flavonoids content was (366.2 ± 17.0 and 126.6 ± 0.2 mg QE/g), and proanthocyanins content was (161.8 ± 0.6 and 70.2 ± 0.6 mg CE/g). The AgPtNPs displayed a greater ability to scavenge free radicals, especially DPPH and ABTS (IC50 19.5 and 21.6 µg/mL) respectively when compared with AgNPs and ascorbic acid. Besides, the AgPtNPs had a higher ferric reducing antioxidant power (FRAP) (44.1 mg GAE/g) when compared to AgNPs (18.5 mg GAE/g). Moreover, the AgPtNPs showed a two-fold antimicrobial activity towards pathogenic microbes compared to AgNPs and a selective cytotoxic potency towards MCF-7 breast cancer cell line compared to HEK 293 normal cell line. In summary, these fascinating bioactivities displayed by the AgPtNPs highlighted their potential in therapeutic biomedical applications.

中文翻译：

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从斑鸠菊提取物合成的新型银铂双金属纳米合金：抗氧化、抗菌和细胞毒活性

摘要 在这项研究中，首次使用乙醇斑斑斑鸠菊属植物提取物合成了具有良好治疗活性的包含银和铂的双金属纳米粒子。双金属银铂纳米粒子 (AgPtNPs) 使用固态技术进行表征，包括紫外-可见光谱、傅里叶变换红外光谱 (FTIR)、透射电子显微镜 (TEM) 和能量色散 X 射线光谱 (EDX) 技术。内部形态结构表明，AgPtNPs 是球形的，直径约为 35.5 ± 0.8 nm，而 FTIR 证实了植物成分对纳米颗粒的有效覆盖和形成。来自 V 的乙醇提取物的绿色合成纳米颗粒的多酚含量。mespilifolia（AgNPs 和 AgPtNPs）的总酚含量为（28.0 ± 0.8 和 13.6 ± 0.1 mg GAE/g），而黄酮类化合物的含量为（366.2 ± 17.0 和 126.6 ± 0.2 mg QE/g），原花青素含量为161.8 ± 0.6 和 70.2 ± 0.6 毫克 CE/克）。与 AgNPs 和抗坏血酸相比，AgPtNPs 显示出更强的清除自由基的能力，尤其是 DPPH 和 ABTS（IC50 分别为 19.5 和 21.6 µg/mL）。此外，与 AgNPs (18.5 mg GAE/g) 相比，AgPtNPs 具有更高的铁还原抗氧化能力 (FRAP) (44.1 mg GAE/g)。此外，与 AgNPs 相比，AgPtNPs 对病原微生物显示出两倍的抗菌活性，并且与 HEK 293 正常细胞系相比，对 MCF-7 乳腺癌细胞系具有选择性的细胞毒性。总之，