Ndikau Michael, Noah Naumih M, Andala Dickson M, Masika Eric
Chemistry Department, Kenyatta University, P.O. Box 43844, Nairobi 00100, Kenya.
School of Pharmacy and Health Sciences, United States International University Africa, P.O. Box 14634, Nairobi 00800, Kenya.
Int J Anal Chem. 2017;2017:8108504. doi: 10.1155/2017/8108504. Epub 2017 Feb 20.
The wide-scale application of silver nanoparticles (AgNPs) in areas such as chemical sensing, nanomedicine, and electronics has led to their increased demand. Current methods of AgNPs synthesis involve the use of hazardous reagents and toxic solvents. There is a need for the development of new methods of synthesizing AgNPs that use environmentally safe reagents and solvents. This work reports a green method where silver nanoparticles (AgNPs) were synthesized using silver nitrate and the aqueous extract of fruit rind as the reductant and the capping agent. The optimized conditions for the AgNPs synthesis were a temperature of 80°C, pH 10, 0.001 M AgNO, 250 g/L watermelon rind extract (WMRE), and a reactant ratio of 4 : 5 (AgNO to WMRE). The AgNPs were characterized by Ultraviolet-Visible (UV-Vis) spectroscopy exhibiting a at 404 nm which was consistent with the spectra of spherical AgNPs within the wavelength range of 380-450 nm, and Cyclic Voltammetry (CV) results showed a distinct oxidation peak at +291 mV while the standard reference AgNPs (20 nm diameter) oxidation peak occurred at +290 mV, and Transmission Electron Microscopy (TEM) revealed spherical shaped AgNPs. The AgNPs were found to have an average diameter of 17.96 ± 0.16 nm.
银纳米颗粒（AgNPs）在化学传感、纳米医学和电子等领域的广泛应用导致其需求不断增加。目前合成AgNPs的方法涉及使用危险试剂和有毒溶剂。因此，需要开发使用环境安全试剂和溶剂来合成AgNPs的新方法。这项工作报道了一种绿色方法，即使用硝酸银和果皮水提取物作为还原剂和封端剂来合成银纳米颗粒（AgNPs）。合成AgNPs的优化条件为：温度80°C、pH值10、0.001 M硝酸银、250 g/L西瓜皮提取物（WM，西瓜皮提取物），以及反应物比例4∶5（硝酸银与WMRE）。通过紫外可见（UV-Vis）光谱对AgNPs进行表征，其在404 nm处有一个峰，这与380-450 nm波长范围内球形AgNPs的光谱一致；循环伏安法（CV）结果显示在+291 mV处有一个明显的氧化，而标准参比AgNPs（直径20 nm）的氧化峰出现在+290 mV处；透射电子显微镜（TEM）显示为球形AgNPs。发现AgNPs的平均直径为17.96±0.16 nm。
