Biosynthesized silver nanoparticles for electrochemical detection of bromocresol green in river water

Abstract

In this study, silver nanoparticles (AgNPs)-based electrochemical sensor has been reported for assessing bromocresol green (BG) in river water. Firstly, AgNPs were greenly produced using the aqueous extract of Ficus sycomorus leaves. Then, the AgNP-modified glassy carbon (GC) electrode was prepared using the sticking method. AgNPs were characterized using transmission electron microscope (TEM), X-ray diffraction (XRD), square wave voltammetry (SWV) and scanning electron microscope (SEM). TEM and SEM were used for determining the size of AgNPs before and after adsorption, respectively. The results show that there was an increase in AgNP size from 20 to 30 nm. Additionally, XRD was used for characterizing the crystal nature of AgNPs, while SWV exhibited a characteristic oxidation peak of AgNPs at 0.06 V. Moreover, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used for characterizing the catalytic effect of AgNPs. BG as a targeted pollutant was detected at AgNPs/GC based on its oxidation through proton and electron transfer. Two peaks corresponding to the monomer and polymer oxidation were detected. The monomer- and polymer-based sensors have revealed a linear range of 2.9 × 10 −5 to 2.1 × 10 −4 mole l −1 and low detection limits (LODs) of 1.5 × 10 −5 and 1.3 × 10 −5 mole l −1 , respectively.

Carbohydrate polymer-supported metal and metal oxide nanoparticles for constructing electrochemical sensors

“…The backward current was enhanced in presence of AgNPs, leading to an increase in the net peak current, which is a combination of the forward and backward current. 54 Fig. 2 shows how the presence of AgNPs as a redox mediator enhances the oxidation of bromocresol green dye.…”

“…Fig.2Schematic representation of the detection of bromocresol green dye using AgNPs as a redox mediator 54. …”