Development of fungal biocathode based Microbial fuel cell and laccase-based biosensor for Biodegradation and detection of Chlorpyrifos organophosphate

Abstract

The widespread utilization of hazardous and tenacious pesticides in agriculture has sparked research into new, high-performing, low-cost and quick analytical strategies to mitigate and detect their residue levels in the environment and food. Therefore, experimental setup was divided into two courses including biodegradation and biosensing of chlorpyrifos. A laboratory-scale dual chambered Microbial Fuel Cell (MFC) is employed for the biodegradation of chlorpyrifos using fungal strains capable of efficient degrading 98% of pesticide (50 mg/L) in 48h respectively at pH 7. Spectrophotometric and Fourier transform infrared (FTIR) data revealed that pesticide was effectively degraded and the results obtained approximately 81% Chemical Oxygen Demand (COD) removal in the system. Bio-electrochemical degradation of the pollutant executed in fungal MFC was coupled with simultaneous generation of electricity as well. The maximal cell potential was recorded to be 706mV in fungal MFC systems with corresponding power densities of 276.9mWm-2 respectively. Moreover, In-cell experiments evaluated by cyclic voltammetry (CV) and chronoamperometry (CA) were performed in bioelectrodes. Maximum electron transfer of 27.35 mA under applied voltage of -1 to +1 V (CV) and current densities of 10.66mAcm−2 (CA) were observed in cathodic compartment where degradation of pollutant were accomplished. The outcomes of this study suggested that in matter of the effective removal of several organic composites and energy recovery, the MFC appeared to be a promising method for the treatment of ecological pollutant i.e., chlorpyrifos at biocathodes relative to COD removal and output power density. 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. This research focuses on the construction and testing of a novel biosensor based on fungal laccase for monitoring the chlorpyrifos. Partially purified laccase obtained from fungus (Aspergillus niger) was initially immobilized in a chemically and thermally treated carbon felt (CF) electrodes by physical adsorption. Biosensing of different concentration of pesticide was carried out in terms of enzyme activity inhibition corresponding to electric signal (I) generation at an applied voltage of DRSML QAU vi - 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 biosensor 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 concentrations by developed biosensor indicated outcomes reliable with those attained via other studies, which authenticate the technique and its benefit for the quantification of the toxic pollutantin less time