Al-Gethami Wafa, Alhashmialameer Dalal, Al-Qasmi Noha, Ismail Sameh H, Sadek Ahmed H
Chemistry Department, Faculty of Science, Taif University, Al-Hawiah, Taif City P.O. Box 11099, Saudi Arabia.
Faculty of Nanotechnology for Postgraduate Studies, Sheikh Zayed Campus, Cairo University, 6th October City, Giza 12588, Egypt.
Nanomaterials (Basel). 2022 Oct 15;12(20):3620. doi: 10.3390/nano12203620.
Pb(II) is a significant contaminant that is known to have negative effects on both humans and animals. Recent industrial operations have exacerbated these consequences, and their release of several contaminants, including lead ions, has drawn attention to the potential effects on human health. Therefore, there is a lot of interest in the rapid, accurate, and selective detection of lead ions in various environmental samples. Sensors-based nanomaterials are a significant class among the many tools and methods developed and applied for such purposes. Therefore, a novel green synthesized cobalt ferrite (CoFeO) nanoparticles and functionalized CoFeO/Ca-alginate nanocomposite was designed and successfully synthesized for the fabrication of nanoparticles and nanocomposite-coated quartz crystal microbalance (QCM) nanosensors to detect the low concentrations of Pb(II) ions in the aqueous solutions at different temperatures. The structural and morphological properties of synthesized nanoparticles and nanocomposite were characterized using different tools such as X-ray diffraction (XRD), N adsorption-desorption isotherm, dynamic light scattering (DLS), zeta potential analyzer (ζ-potential), atomic force microscopy (AFM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDX). The QCM results revealed that the green synthesized CoFeO nanoparticles and functionalized CoFeO/Ca-alginate nanocomposite-coated QCM nanosensors exhibited high sensitivity, stability, and rapid detection of Pb(II) ions in the aqueous solutions at different temperature. The lowest detection limit for Pb(II) ions in the aqueous solutions could reach 125 ng, which resulted in a frequency shift of 27.49 ± 0.81, 23.63 ± 0.90, and 19.57 ± 0.86 Hz (Δ) for the QCM detector coated with green synthesized CoFeO nanoparticles thin films, and 25.85 ± 0.85, 33.87 ± 0.73, and 6.87 ± 0.08 Hz (Δ) for the QCM detector coated with CoFeO/Ca-Alg nanocomposite thin films in a real-time of about 11, 13, and 13 min at 25 °C, 35 °C, and 45 °C, respectively. In addition, the resonance frequency change results showed the superiority of functionalized CoFeO/Ca-alginate nanocomposite coated QCM nanosensor over CoFeO nanoparticles towards Pb(II) ions detecting, which attributed to the beneficial properties of alginate biopolymer.
铅（II）是一种重要的污染物，已知会对人类和动物产生负面影响。近期的工业活动加剧了这些后果，其释放的包括铅离子在内的多种污染物引发了人们对其对人类健康潜在影响的关注。因此，人们对快速、准确且选择性地检测各种环境样品中的铅离子有着浓厚兴趣。基于传感器的纳米材料是为此目的而开发和应用的众多工具和方法中的重要一类。因此，设计并成功合成了一种新型的绿色合成钴铁氧体（CoFeO）纳米颗粒以及功能化的CoFeO/海藻酸钙纳米复合材料，用于制造纳米颗粒和纳米复合材料包覆的石英晶体微天平（QCM）纳米传感器，以检测不同温度下水溶液中低浓度的铅（II）离子。使用不同工具对合成的纳米颗粒和纳米复合材料的结构和形态特性进行了表征，如X射线衍射（XRD）、N吸附 - 脱附等温线、动态光散射（DLS）、zeta电位分析仪（ζ - 电位）、原子力显微镜（AFM）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）以及能量色散X射线光谱（EDX）。QCM结果表明，绿色合成的CoFeO纳米颗粒和功能化的CoFeO/海藻酸钙纳米复合材料包覆的QCM纳米传感器在不同温度下对水溶液中的铅（II）离子表现出高灵敏度、稳定性和快速检测能力。水溶液中铅（II）离子的最低检测限可达125 ng，这使得涂覆有绿色合成CoFeO纳米颗粒薄膜的QCM检测器的频率偏移分别为27.49±0.81、23.63±0.90和19.57±0.86 Hz（Δ），而涂覆有CoFeO/海藻酸钙纳米复合材料薄膜的QCM检测器在25°C、35°C和45°C时，在约11、13和13分钟的实时检测中频率偏移分别为25.85±0.85、33.87±0.73和6.87±0.08 Hz（Δ）。此外，共振频率变化结果表明，功能化的CoFeO/海藻酸钙纳米复合材料包覆的QCM纳米传感器在检测铅（II）离子方面优于CoFeO纳米颗粒，这归因于海藻酸生物聚合物的有益特性。
