Mesoporous silica nanoparticles, functionalized by APTES, were used to modify glassy carbon electrodes (GCE) and their performance was assessed for the accurate quantification of trace Pb ions under electrochemical methods. Mesoporous (3-aminopropyl) triethoxysilane modified-silica particles (SiO-APTES), of about 200 nm, were synthesized by the modified Stӧber method in presence of cetyltrimethylammonium bromide. Silica particles were characterized by X-Ray diffraction analysis, scanning electron microscopy, infrared spectrum analysis, and electrochemical techniques such as cyclic voltammetry and electrochemical impedance spectroscopy (EIS). Furthermore, their mesoporous characteristics were investigated by the analysis of N adsorption/desorption isotherms. The functional groups on the silica particle surface showed remarkable selectivity towards Pb. Various experimental parameters, including incubation time, pH of the buffered solution, and quantity of SiO-APTES deposited on the electrode were systematically investigated to identify optimal operating conditions for the system. After optimization, the sensors covered a working dynamic range from 8.8 × 10 M to 1.2 × 10 M achieving a noteworthy limit of detection of 2.6 × 10 M. Interference studies have demonstrated that GCE/SiO2-APTES electrodes exhibit high sensitivity and specificity for Pb2+ detection, making them a promising tool for rapid and portable detection of this heavy metal. Finally, the feasibility of these electrodes for Pb ions detection was evaluated in real samples such as seawater (obtained from Monastir, Tunisia) and tap water by using the standard addition method. The high accuracy and reliability of the SiO2-APTES modified GCE was demonstrated by the excellent recovery studies, which ranged from 88 to 104% for all spiked samples. The overall finding supports the practical applicability of this sensor for a real-world context and confirms its potential for environmental monitoring.

中文翻译：

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使用功能化二氧化硅纳米颗粒 (SiO2-APTES) 改进电化学传感器，用于高选择性检测铅离子

通过 APTES 功能化的介孔二氧化硅纳米粒子用于修饰玻碳电极 (GCE)，并评估其性能以在电化学方法下准确定量痕量 Pb 离子。在十六烷基三甲基溴化铵存在下，通过改进的 Stקber 方法合成了约 200 nm 的介孔（3-氨基丙基）三乙氧基硅烷改性二氧化硅颗粒（SiO-APTES）。通过 X 射线衍射分析、扫描电子显微镜、红外光谱分析以及循环伏安法和电化学阻抗谱 (EIS) 等电化学技术对二氧化硅颗粒进行了表征。此外，通过分析N吸附/解吸等温线研究了它们的介孔特性。二氧化硅颗粒表面的官能团对Pb表现出显着的选择性。系统研究了各种实验参数，包括孵育时间、缓冲溶液的 pH 值以及沉积在电极上的 SiO-APTES 数量，以确定系统的最佳操作条件。优化后，传感器的工作动态范围为 8.8 × 10 M 至 1.2 × 10 M，检测限达到了 2.6 × 10 M。干扰研究表明，GCE/SiO2-APTES 电极对 Pb2+ 表现出高灵敏度和特异性检测，使它们成为快速、便携式检测这种重金属的有前途的工具。最后，采用标准添加法在海水（突尼斯莫纳斯提尔）和自来水等实际样品中评估了这些电极用于Pb离子检测的可行性。出色的回收率研究证明了 SiO2-APTES 改良 GCE 的高精度和可靠性，所有加标样品的回收率范围为 88% 至 104%。总体发现支持该传感器在现实世界中的实际适用性，并证实了其在环境监测方面的潜力。