Water pollutants have attracted a great attention because their negative effect on human health. Accordingly, various analytical techniques were investigated to detect the water pollutants as a preliminary step for...

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An electrochemical sensor based on silver nanoparticles (AgNPs) was developed by immobilizing dissolved organic matter (DOM) to interact with AgNPs on a glassy carbon electrode (GC), forming a DOM/AgNP/GC composite. AgNPs have been fabricated and characterized using ultraviolet–visible spectroscopy, fluorescence spectroscopy, and transmission electron microscopy. The immobilization efficiency and stability of the DOM/AgNP/GC composite have been optimized through studying the effects of electrode material type, immobilization technique, sticking duration, supporting electrolyte, and pH using square wave anodic stripping voltammetry. The detection of atrazine (Atz), a common herbicide, in aqueous systems has a great significance because of its toxicity to humans and other animals. The DOM/AgNP/GC composite has been used for Atz assessment under the optimized conditions based on the aggregated and nonaggregated AgNPs. The sensor linear range is between 20 and 220 μg/L for both aggregated and nonaggregated AgNP-based sensors. Atz could also be detected on the basis of its electrochemical oxidation at DOM/AgNP/GC with a linear range of 10–140 μg/L. Both sensors have been employed for the assessment of Atz in natural water with acceptable recovery values.

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Silver nanoparticles (AgNPs) were biologically synthesized in an eco-friendly manner using aqueous leaf extract ofOriganum majoranaplant and silver nitrate (AgNO3) solution. Size, shape, and crystallinity of the biosynthesized AgNPs were determined by using a transmission electron microscope (TEM). Zeta potential analyzer was used to prove the stability of the metallic nanoparticles, while Fourier transform infrared spectroscopy was used to identify the bioreducing and capping agents. AgNPs were electrochemically investigated using cyclic voltammetry (CV), while the optical properties of the metallic nanoparticles were studied using UV-Vis and fluorescence spectroscopies. According to TEM images, AgNPs are spherical with an average size of 35 nm. TEM also refers to the presence of mono and polycrystalline AgNPs. The value of zeta potential (−39 mV) proved the stability of AgNPs caused by capping molecules ofO. majoranaplant. CV studies showed that AgNPs were electrochemically investigated at 0.39 mV. AgNPs showed a surface plasmon resonance peak at 440 nm, while the emission peak was detected at 466 nm. These nanoparticles are promising for many industrial and medical applications.