In this study, the extract of two strains of cyanobacteria was used for the synthesis of silver nanoparticles (NPs). UV–vis spectroscopy, X-ray diffraction, dynamic light scattering and field emission scanning electron microscopy (FESEM) analyses were carried out to characterise the NPs. The antioxidant activity and heavy metal detection properties were investigated; moreover, their minimum inhibitory concentration and minimum bactericidal concentration against the multi-drug resistant bacteria were determined. The most abundant materials in these extracts were carbohydrates, so the biosynthesis of NPs using exopolysaccharide (EPS) was also investigated. The surface plasmon resonance of NPs had a peak at 435 nm and EPS NPs at 350–450 nm. The NPs produced by Nostoc sp. IBRC-M5064 extract revealed the face-centred cubic (fcc) structure of AgCl, while NPs of N. pruniforme showed the fcc crystalline structure of Ag ₃ PO ₄ and AgCl. The FESEM showed the spherical shape of these NPs. The AgCl/Ag ₃ PO ₄ colloid, in comparison with AgCl, showed better antioxidant activity and antibacterial effect. The heavy metal detection analysis of NPs revealed that the NPs of both stains involved in Hg (NO ₃ ) ₂ detection.

中文翻译：

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利用蓝藻绿色合成 AgCl/Ag3PO4 纳米颗粒及其抗菌、比色检测重金属和抗氧化性能的评价

在这项研究中，两种蓝藻菌株的提取物被用于合成银纳米粒子 (NPs)。进行紫外-可见光谱、X 射线衍射、动态光散射和场发射扫描电子显微镜 (FESEM) 分析以表征纳米颗粒。研究了抗氧化活性和重金属检测性能；此外，测定了它们对多重耐药菌的最低抑菌浓度和最低杀菌浓度。这些提取物中最丰富的材料是碳水化合物，因此还研究了使用胞外多糖 (EPS) 生物合成 NPs。NPs 的表面等离子共振在 435 nm 处有一个峰值，EPS NPs 在 350-450 nm 处有一个峰值。NPs 由发菜sp。IBRC-M5064 提取物揭示了 AgCl 的面心立方 (fcc) 结构，而 NPsN. pruniforme_{显示了Ag 3} PO ₄和AgCl的fcc晶体结构 。FESEM 显示了这些 NPs 的球形。AgCl/Ag ₃ PO ₄胶体与AgCl相比，表现出更好的抗氧化活性和抗菌作用。NPs的重金属检测分析表明，两种染料的NPs都参与了Hg (NO ₃ ) ₂的检测。