High Visual Colorimetric Determination of F- Ions by Exploiting the Inhibition of Oxidase Mimicking Activity of FeMnO4@GQD Nanocomposite

Human health is significantly impacted by fluorides in water.Too much fluoride consumption through drinking water causes chronic dental and bones diseases. A trace number of fluorides in drinking water can be determined, which is immensely vital for human health. In the current study, we have designed a visual colorimetric chemosensor assay using the brilliant oxidase mimicking activity of biosynthesized FeMnO4@GQD nanocomposite. FeMnO4@GQD nanocomposites showed excellent mimicking activity in mild acid medium p(H)-5, and obtained a V-max value of 1.71603x10(-6) and an important K-m value of 0.0684 mM based on Hanes-Woolf kinetics. The robust nanocomposites were shown to be significant stability for detecting oxidases under conditions. As a consequence, oxidase-like activity was inhibited in the presence of fluoride ions. A linear correlation was established by the development of blue colour with fluoride ions concentration and appeared at a low limit of detection of 1.2 mu g/ml without interfering with other common ions.