Fabrication of self-assembled gold–magnetic laccase composite electrode using a four-stage magnetic field and its application in an integrated temperature – Controlled system for enhanced electrochemical detection of catechol

Abstract

A novel electrochemical biosensor based on a gold–magnetic nanoparticle–laccase composite (Fe₃O₄@Au-MUA-LAC) was developed for the detection of catechol (CC). The sensor leverages Fe₃O₄ nanoparticles as carriers to create a Fe₃O₄@Au core–shell structure, which is further functionalized with laccase to enhance electrocatalytic activity. The application of an external magnetic field facilitates the orderly arrangement of magnetic materials on the electrode surface, thereby increasing the catalytic surface roughness of materials and promoting electrocatalytic reactions. In addition, a custom-designed thermostat with a digital display was integrated into the experimental setup, offering an innovative platform for examining temperature effects on electrochemical detection. Optimization of sensor fabrication conditions enabled the successful detection of CC. The sensor demonstrated a linear detection range from 0 to 500 μM, a detection limit of 0.458 μM, and a sensitivity of 24.7 μA/Mm. Selectivity studies confirmed the biosensor’s reliability in detecting CC in complex water samples. The developed sensor not only provides a rapid and accurate method for monitoring CC in environmental samples but also introduces a new approach to studying temperature’s impact on electrochemistry. The findings underscore the significance of magnetic fields in enhancing the performance of electrochemical biosensors for CC detection.