Abstract

The objective of this investigation is to synthesize and investigate zero-valent iron (ZVI) nanoparticles (NPs) for bioremediation applications. The ZVI-NPs were fabricated by chemical reduction using a ferrous salt solution with poly(N-vinylpyrrolidone) (PVP), used as a stabilizer. The synthesis was conducted with and without ultrasonic treatment. The ZVI NPs were fabricated and characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD) analysis, and Fourier Transform Infrared Spectroscopy (FTIR). Experimental observations demonstrate that depending on synthesis conditions and coordination of stabilizers, NPs with different morphologies are formed. Colloidal solutions of the synthesized NPs were used in antimicrobial activity tests and biofilm formation assays for nine different control microorganisms: Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 15692), Enterococcus faecalis (ATCC 29122), Klebsiella pneumoniae (laboratory isolates), Proteus vulgaris (laboratory isolates), Staphylococcus aureus (ATCC 29213), Bacillus cereus (DSMZ 4312), Bacillus subtilis (ATCC 6633), and Candida albicans (ATCC 10231). All control strains did not show antibacterial effect against PVP-stabilized ZVI NPs synthesized without ultrasonic treatment. However, biofilm results show that the highest absorbance values of the micro-organisms were tested in control wells. Although B. subtilis, E. coli, and K. pneumoniae were observed during biofilm formation, B. cereus, S. aureus, and P. aeruginosa biofilm formation reduced noticeably by Fe⁰/PVP-US (A1) NPs. For control strains, such as E. faecalis and C. albicans, no biofilm formation was observed. For Fe⁰/PVP (A2) NPs, biofilm formation of B. subtilis, E. faecalis, E. coli, K. pneumoniae, P. vulgaris, and C. albicans demonstrated positive effect, and B. cereus, S. aureus, P. aeruginosa showed negative effect. A strategic utilization of nZVI-PVP nanoparticles showed a great potential for effective, efficient, and sustainable bioremediation applications.

摘要

本研究的目的是合成和研究用于生物修复应用的零价铁 (ZVI) 纳米粒子 (NPs)。ZVI-NPs 是用亚铁盐溶液和聚（N-乙烯基吡咯烷酮）（PVP），用作稳定剂。合成在有和没有超声波处理的情况下进行。使用扫描电子显微镜 (SEM)、透射电子显微镜 (TEM)、X 射线粉末衍射 (XRD) 分析和傅里叶变换红外光谱 (FTIR) 制造和表征 ZVI NP。实验观察表明，根据合成条件和稳定剂的配位，形成不同形态的纳米颗粒。合成 NP 的胶体溶液用于九种不同对照微生物的抗菌活性测试和生物膜形成测定：大肠杆菌(ATCC 25922)、铜绿假单胞菌(ATCC 15692)、粪肠球菌(ATCC 29122)、肺炎克雷伯菌（实验室分离物）、普通变形杆菌（实验室分离物）、金黄色葡萄球菌(ATCC 29213)、蜡状芽孢杆菌(DSMZ 4312)、枯草芽孢杆菌(ATCC 6633) 和白色念珠菌(ATCC 10231)。所有对照菌株均未显示对未经超声处理合成的 PVP 稳定的 ZVI NPs 的抗菌作用。然而，生物膜结果表明，在对照孔中测试了微生物的最高吸光度值。虽然在生物膜形成过程中观察到枯草芽孢杆菌、大肠杆菌和肺炎克雷伯菌，但蜡状芽孢杆菌、金黄色葡萄球菌和^{Fe 0} /PVP-US (A1) NPs显着减少了铜绿假单胞菌生物膜的形成。对于对照菌株，例如粪肠球菌和白色念珠菌，没有观察到生物膜形成。对于 Fe ^{0 /PVP (A2) NPs，}枯草芽孢杆菌、粪肠球菌、大肠杆菌、肺炎克雷伯菌、普通假单胞菌和白色念珠菌的生物膜形成显示出积极作用，而蜡状芽孢杆菌、金黄色葡萄球菌、铜绿假单胞菌表现出负面影响。nZVI-PVP 纳米粒子的战略性利用显示出在有效、高效和可持续的生物修复应用方面的巨大潜力。