Alginate-Capped Silver Nanoparticles for Electrochemical Quantification of Crystal Violet in Water

Quantification of toxic dyes in polluted water is essential to environmental monitoring and control. Herein, a novel electrochemical sensor has been developed to quantify crystal violet (CV) using alginate-silver nanoparticles (Alg-AgNPs) fabricated by the direct chemical reduction technique. Alg- AgNPs synthesis was visually indicated, then experimentally confirmed employing an ultraviolet-visible spectrophotometer, which showed AgNP absorption peak at 400   nm, and square wave voltammetry (SWV), which exhibited the AgNP oxidation peak at 0.3   V. Additionally, X-ray diffraction analysis demonstrated the crystalline nature of Alg-AgNP, while transmission electron microscopy showed the spherical/semi-spherical shape of AgNPs with an average particle size of 42.9   nm. The prominent role of Alg-AgNPs in the electrocatalysis of CV oxidation was evidenced using cyclic voltammetry and SWV. AgNP-modified glassy carbon electrode sensor exhibited detection and quantification limits of 0.08 and 0.28   μM, respectively. Additionally, the sensor’s selectivity was demonstrated through interference studies and real-sample analysis.