Abstract

Wood pulping for paper production accounts for bulk of the tree lost, with numerous adverse effects to the environment. In this study, Eucalyptus camaldulensis leaf extract was used for silver nanoparticles synthesis. The nanoparticles were used as functional agent for the valorization of wastepaper. The nanocomposite paper was characterized for physicochemical, antibacterial and cytotoxicity. DLS and TEM revealed a spherical nano-sized particle with effective diameters of 138.6 nm and mean size of 13.11 nm, respectively while zeta potential was − 35.85 mV. Minimum inhibitory and minimum bactericidal concentrations of silver nanoparticles ranged from 0.99 to 1.99 µg/mL and 3.98–15.91 µg/mL respectively. UV–vis spectra presented a peak at 427 nm, indicating the surface plasmon resonance band of silver in the paper. SEM and EDX showed uniform distribution of silver nanoparticles, whereas EDX and ICP-OES results indicated Ag concentration of 0.1%Wt and 0.0112 µg/cm², respectively. Antibacterial efficacy of the paper demonstrated a bactericidal effect against Bacillus cereus and Escherichia coli O157:H7 with > 3log reduction in CFU/mL after 3 h of treatment and bacteriostatic effect against Listeria monocytogenes and Staphylococcus aureus. In addition, cytotoxicity against HEK293T and Caco-2 cells revealed > 80% cell viability. Results indicate that valorization of wastepaper through functionalization with bioactive silver nanoparticles could serve as a sustainable waste management approach.

Graphic Abstract

中文翻译：

---

通过抗菌素功能化与生物银纳米颗粒（一种可持续的包装复合材料）对废纸进行增值

摘要

用于造纸的木浆占树木损失的大部分，对环境造成许多不利影响。在这项研究中，桉桉叶提取物用于银纳米颗粒的合成。纳米粒子用作废纸的增值功能剂。该纳米复合纸具有理化，抗菌和细胞毒性的特征。DLS和TEM显示球形纳米颗粒，有效直径分别为138.6 nm和平均尺寸为13.11 nm，而zeta电位为− 35.85 mV。银纳米颗粒的最小抑菌和最小杀菌浓度分别为0.99至1.99 µg / mL和3.98–15.91 µg / mL。紫外可见光谱在427 nm处出现一个峰，表明纸张中银的表面等离振子共振带。SEM和EDX显示银纳米颗粒分布均匀，而EDX和ICP-OES结果表明Ag浓度为0.1％Wt和0.0112 µg / cm ²， 分别。本文的抗菌功效证明了对蜡状芽孢杆菌和大肠杆菌O157：H7的杀菌作用，处理3小时后CFU / mL降低了> 3log以上，并且对单核细胞增生李斯特菌和金黄色葡萄球菌具有抑菌作用。此外，针对HEK293T和Caco-2细胞的细胞毒性显示> 80％的细胞活力。结果表明，通过使用生物活性银纳米颗粒进行功能化来实现废纸增值可以用作可持续的废物管理方法。

图形摘要