Aiming at enhancing the detection of phenolic contaminants in high-temperature environments, wedeveloped a thermoregulatory electrochemical biosensor based on the tyrosinase-immobilized electroactivephase-change microcapsules. The microcapsules were fabricated by engulfing n-eicosane as a phasechangematerial core in a TiO2 shell, followed by depositing with an electroactive hybrid layer comprisingthe polypyrrole matrix and tyrosinase-immobilized Fe3O4 nanoparticles. The resultant microcapsulesshow a well-defined core–shell microstructure and a regular spherical morphology, together with thedesired chemical compositions and structures. Acting as a biosensing electrode material, the microcapsulesexhibit a high latent heat capacity of around 150 J/g to implement microenvironmental temperatureregulation for the biosensor through reversible phase transitions of their n-eicosane core. Thisenables the developed biosensor to obtain a higher enzyme activity and more sensitive biosensing performanceat high assay temperatures when compared to conventional tyrosinase biosensors, resultingin a high sensitivity of 0.102 (lAL)/lmol and a lower detection limit of 3.409 lmol/L for catechol detection. Based on a unique integration of phase-change microcapsules and immobilized tyrosinase in theworking electrode, the electrochemical biosensor developed in this study has found a practical applicationfor high-sensitive reorganization and high-accurate determination of phenolic contaminants inindustrial wastewaters over a wide working temperature range.