School of Chemical & Biotechnology, SASTRA University, Thanjavur-613401, Tamil Nadu, India.
Analyst. 2013 Aug 7;138(15):4370-7. doi: 10.1039/c3an00320e. Epub 2013 Jun 5.
In the present study, the syntheses of crystalline silver and gold nanoparticles (NPs) has been demonstrated in a green and environmentally friendly approach using citrus fruit extracts (lemon, Citrus limon (Cl-1) and sweet orange, Citrus limetta (Cl-2)). In addition, potentially hazardous metal ion sensing properties of these NPs in aqueous solution has been explored. Cl-1 and Cl-2 that predominantly contained citric and ascorbic acid, exhibited different reducing abilities towards silver and gold ions into NPs. Cl-1 reduces silver ions into AgNPs only in the presence of sunlight whereas AuNPs from gold ions were formed without exposure to sunlight. In contrast, Cl-2 converts both silver and gold ions into the corresponding NPs in the absence of sunlight. The colorimetric sensor studies of these green synthesized AgNPs (Cl-1-AgNPs) showed selective sensing of the potentially hazardous Hg(2+) ion in water at micromolar concentrations. More importantly, green synthesized Cl-1-AgNPs sensor systems detected Hg(2+) ions in water in a wide pH range (3.2 to 8.5).
在本研究中，使用柑橘类水果提取物（柠檬，Citrus limon（Cl-1）和甜橙，Citrus limetta（Cl-2））以绿色环保的方式展示了结晶银和金纳米粒子（NP）的合成。此外，还探索了这些 NP 在水溶液中潜在危险金属离子传感性能。Cl-1 和 Cl-2 主要含有柠檬酸和抗坏血酸，对银离子和金离子具有不同的还原能力成 NP。Cl-1 仅在阳光存在下将银离子还原成 AgNPs，而 AuNPs 则是在没有暴露于阳光下的情况下从金离子形成的。相比之下，Cl-2 在没有阳光的情况下将银和金离子都转化为相应的 NPs。这些绿色合成的 AgNPs（Cl-1-AgNPs）的比色传感器研究表明，在微摩尔浓度下对水中潜在危险的 Hg（2+）离子具有选择性感应。更重要的是，绿色合成的 Cl-1-AgNPs 传感器系统在宽 pH 范围（3.2 至 8.5）中检测到水中的 Hg（2+）离子。
