The present study reports the green synthesis of triangular ZnO nanoparticles (G-ZnO NPs) using Azadirachta indica leaves extract, and a shape dependent density functional investigation for ZnO NPs on their antimicrobial activity. The X-ray diffraction (XRD) analysis shows the synthesized G-ZnO NPs are well crystalline in nature and calculated grain size is found to be 60–65 nm. The Fourier transforms infrared spectroscopy (FT-IR) represents that the functional group and capping agents are well attached to the nanoparticles, and the bands located near 500.8 cm⁻¹, 459.07 cm⁻¹ and 418.57 cm⁻¹ represents G-ZnO NPs. Scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDS) confirmed the presence of the synthesized G-ZnO nanoparticles with an average size range 100–200 nm. The synthesized G-ZnO NPs are found to be in the triangular shape. A detail theoretical investigation under density functional framework shows that our synthesized triangular ZnO nanoparticles are better candidate for biological interactions compared to the prototypical spherical counterpart. The synthesized G-ZnO nanoparticles using A. indica leaves extract in triangular shape are found to show significant antimicrobial activity against Escherichia coli and Bacillus subtilis indicating a better alternative to the typical chemical methods.

Graphic Abstract

中文翻译：

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用印楝叶提取物绿色合成三角形 ZnO 纳米颗粒及其具有显着抗菌活性的形状依赖性：联合实验和理论研究

本研究报告了使用印楝叶提取物绿色合成三角形 ZnO 纳米粒子 (G-ZnO NPs) ，以及对 ZnO NPs 对其抗菌活性的形状依赖性密度泛函研究。X 射线衍射 (XRD) 分析表明合成的 G-ZnO NPs 具有良好的结晶性，计算出的晶粒尺寸为 60-65 nm。傅里叶变换红外光谱 (FT-IR) 表明官能团和封端剂与纳米颗粒很好地连接，并且谱带位于 500.8 cm ^-1、459.07 cm ^-1和 418.57 cm ^{-1 附近}代表 G-ZnO NPs。扫描电子显微镜 (SEM) 和能量色散 X 射线分析 (EDS) 证实了合成的 G-ZnO 纳米粒子的存在，其平均尺寸范围为 100-200 nm。发现合成的 G-ZnO NPs 呈三角形。密度泛函框架下的详细理论研究表明，与原型球形对应物相比，我们合成的三角形 ZnO 纳米粒子更适合用于生物相互作用。发现使用三角形的籼稻叶提取物合成的 G-ZnO 纳米颗粒对大肠杆菌和枯草芽孢杆菌显示出显着的抗菌活性，表明是典型化学方法的更好替代品。

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