Recent advances in silver nanoparticle-based electrochemical sensors for determining organic pollutants in water: a review

Water pollutants have attracted great attention because of their negative effect on human health. Accordingly, various analytical techniques have been investigated to detect water pollutants as a preliminary step for their control. This review highlights silver nanoparticles (AgNPs) as promising electrochemical probes studied for detecting organic pollutants. Electrochemical sensors can be fabricated by modifying electrode surfaces using AgNPs via different techniques, such as electrochemical deposition, drop casting, spin coating, sticking, and transfer sticking, as well as carbon paste-based modification. AgNPs at electrode surfaces can be identified by their stripping to form Ag+ with a particular oxidation peak. Additionally, they can be detected indirectly by catalyzing electrochemical reactions. AgNP-modified electrodes are known for their increased surface area and superior conductivity compared with unmodified electrodes. They can detect various inorganic and organic analytes on the basis of the electrochemical responses of the AgNPs or the analyte. The mechanisms of AgNP-modifier-based electrochemical sensors (including AgNPs aggregation, displacement, inhibition, and amplification) and analyte-based electrochemical sensors (including oxidation and reduction) have been highlighted as efficient tools for detecting organic pollutants. Overall, AgNP-based electrochemical sensors are considered a promising tool for determining various organic pollutants in water.