Natural enzymes, while catalytically proficient, are often limited by their sensitivity to environmental conditions and the complexity of their extraction and storage. This has driven research towards the development of robust, cost-effective, and readily available enzyme mimics. Among these, transition metal borides have emerged as promising candidates, leveraging their unique electronic and catalytic properties to emulate enzymatic functions. In this study, we introduce the synthesis of amorphous metal boride nanoparticles through a facile chemical reduction method under chilled conditions. For the first time, these nanoparticles are demonstrated to possess intrinsic peroxidase-like activity, with the 4Fe-Ni-B variant exhibiting the highest activity among the samples tested. The density functional the-ory (DFT) revealed that the addition of nickel enhanced the response of 4Fe-Ni-B to hydrogen peroxide and a synergistic ef-fect between Ni2+ and Fe3+ ions, which facilitated the conversion of Fe3+ to Fe2+ and thus improved the catalytic efficiency. Expanding the utility of these nanozymes, We introduce a colorimetric sensor for swift H2O2 and GSH detection, showcasing the versatility of transition metal borides in analytical applications. This work advances binary metal borides as artificial enzymes and deepens the comprehension of nanozyme de-sign, paving the way for next-generation artificial enzymes with customized catalytic profiles.