Division of Molecular and Cellular Biology, Department of Biotechnology, Kalasalingam University, Anand Nagar, Krishnankoil 626190, Tamil Nadu, India.
Colloids Surf B Biointerfaces. 2011 Sep 1;86(2):353-8. doi: 10.1016/j.colsurfb.2011.04.019. Epub 2011 Apr 16.
This study aims at developing a new eco-friendly process for the synthesis of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) using purified URAK. URAK is a fibrinolytic enzyme produced by Bacillus cereus NK1. The enzyme was purified and used for the synthesis of AuNPs and AgNPs. The enzyme produced AgNPs when incubated with 1 mM AgNO3 for 24 h and AuNPs when incubated with 1 mM HAuCl4 for 60 h. But when NaOH was added, the synthesis was rapid and occurred within 5 min for AgNPs and 12 h for AuNPs. The synthesized nanoparticles were characterized by a peak at 440 nm and 550 nm in the UV-visible spectrum. TEM analysis showed that AgNPs of the size 60 nm and AuNPs of size 20 nm were synthesized. XRD confirmed the crystalline nature of the nanoparticles and AFM showed the morphology of the nanoparticle to be spherical. FT-IR showed that protein was responsible for the synthesis of the nanoparticles. This process is highly simple, versatile and produces AgNPs and AuNPs in environmental friendly manner. Moreover, the synthesized nanoparticles were found to contain immobilized enzyme. Also, URAK was tested on RAW 264.7 macrophage cell line and was found to be non-cytotoxic until 100 μg/ml.
本研究旨在开发一种使用纯化的 URAK 合成银纳米粒子（AgNPs）和金纳米粒子（AuNPs）的环保新工艺。URAK 是由蜡状芽孢杆菌 NK1 产生的纤溶酶。该酶经过纯化后，用于合成 AuNPs 和 AgNPs。当孵育 1mM AgNO3 24 小时时，酶会产生 AgNPs，而孵育 1mM HAuCl4 60 小时时则会产生 AuNPs。但是，当加入 NaOH 时，合成会迅速发生，AgNPs 仅需 5 分钟，AuNPs 则需 12 小时。合成的纳米粒子在紫外-可见光谱中表现出 440nm 和 550nm 处的峰值。TEM 分析表明，AgNPs 的尺寸为 60nm，AuNPs 的尺寸为 20nm。XRD 证实了纳米粒子的结晶性质，AFM 则显示纳米粒子的形态为球形。FT-IR 表明蛋白质是合成纳米粒子的原因。该过程非常简单、通用，并且以环保的方式生产 AgNPs 和 AuNPs。此外，还发现合成的纳米粒子含有固定化酶。此外，URAK 在 RAW 264.7 巨噬细胞系上进行了测试，直到 100μg/ml 时才发现其无细胞毒性。
