Validating role of different enzymes (laccases and catalases) based voltammetric biosensors in detection of pesticide and dye

Abstract

The widespread utilization of hazardous and tenacious pesticides and azo dye in agriculture as well as textile industry respectively has sparked research into new, high-performing, low-cost and quick analytical strategies to mitigate their residue levels in the environment and food. An enzyme based biosensor has been considered as rapid biosensing tool for detection of toxicity and environmental monitoring of different contaminants as compared to previously existing conventional. Pesticide detection based on enzyme inhibition have been reported previously, however, for the dye it is reported for the first time in this study. This research focuses on the construction and testing of a novel biosensor based on fungal laccase and bacterial catalase for monitoring the chlorpyrifos and Reactive Red 195 (RR195). Partially purified laccase obtained from fungus (Aspergillus niger) and Catalase from bacteria (Staphylococcus aureus) was initially immobilized in a chemically and thermally treated carbon felt (CF) electrodes by physical adsorption. Biosensing of different concentration of pesticide and dye was carried out in terms of enzyme activity inhibition corresponding to electric signal (I) generation at an applied voltage of −1 to +1 through voltammetric analysis. Increase in concentrations of pollutants (10 ugL−1-30 mgL−1) was significantly correlated with decline in current (I) output. Effectiveness of biosensors is depicted by good repeatability, stability, and low limit of detection with insignificant interference of other compounds. The reusability of the enzyme based electrode was confirmed even after 90 days with a slight variation in current (I) peaks. The determination of varying chlorpyrifos and RR195 concentrations by developed biosensors indicated outcomes reliable with those attained via other studies, which authenticate the technique and its benefit for the quantification of these pollutants in less time.