A LOW-COST LACCASE BIOSENSOR FOR ON-SITE MONITORING OF PHENOLIC POLLUTANTS IN AQUATIC ENVIRONMENTS

Abstract

Phenolic compounds are toxic environmental pollutants commonly present in industrial wastewater and textile dye effluents. In this study, a laccase-based paper biosensor was developed for the rapid and cost-effective detection of phenolic compounds in water samples. The biosensor was fabricated using fungal laccase immobilized on Whatman filter paper with MBTH as a chromogenic substrate. In the presence of phenolic compounds, sa visible pink to maroon coloration was produced due to enzymatic oxidation reactions. Optimization studies showed that 2 mg/mL laccase and 24 mM MBTH provided the highest colour response. The biosensor exhibited sensitivity over a guaiacol concentration range of 1–512 µM with a detection limit of 1 µM. Sewage water and textile dye effluent samples collected from Faisalabad were successfully analyzed using the developed biosensor. Colour intensity was quantified through RGB image analysis using ImageJ software. The results demonstrated that the developed biosensor is rapid, portable, inexpensive, and suitable for environmental monitoring of phenolic pollutants in wastewater samples.