<p>A novel 2-mercaptobenzothiazole (2-MBT) detection method is introduced based on ultrathin PtRuFeCoRhW high-entropy alloy nanorods (HEANRs) synthesized via a solvothermal-coreduction strategy. These HEANRs contained numerous defects and atomic steps, providing abundant active sites. It exhibited peroxidase (POD)-like activity for its entropy-driven catalytic synergy and modified electronic structure, which was utilized to construct a colorimetric sensing platform. The platform operates via competitive inhibition between 2-MBT and 3,3’,5,5’-tetramethylbenzidine (TMB) oxidation, enabling ultrasensitive 2-MBT detection with a linear range of 1–7 µM (<i>R</i>^<i>2</i> = 0.997) and a detection limit of 0.42 µM (<i>S</i>/<i>N</i> = 3). Notably, the sensor demonstrates reliable performances in practical analysis of rubber wastewater. This work provides an efficient method for detecting 2-MBT. It also demonstrates that entropy-driven structural engineering is a promising strategy for designing advanced high-entropy materials. This research advances high-entropy-initiated catalysis and offers a versatile platform for environmental remediation, addressing a broad range of analytical challenges.</p> Graphical abstract <p></p>