Electronic structure modulation of ultrathin PtRuMoCoNi high-entropy alloy nanowires for boosting peroxidase-like activity and sensitive colorimetric determination of isoniazid and hydrazine.

Self-supported ultrathin PtRuMoCoNi high-entropy alloy nanowires (HEANWs) were synthesized by a one-pot co-reduction method, whose peroxidase (POD)-like activity and catalytic mechanism were elaborated in detail. As expected, the PtRuMoCoNi HEANWs showed excellent POD-like activity. It can quickly catalyze the oxidization of colorless 3,3',5,5'-tetramethylbenzidine (TMB) to blue TMB through decomposition of HO to superoxide radicals. Notably, isoniazid and hydrazine effectively scavenge the as-produced superoxide radicals and reduce the blue TMB, showing high reduction ability and antioxidant property. Thus, the PtRuMoCoNi HEANW-derived colorimetric method was developed for determination of isoniazid and hydrazine, which exhibited the linear ranges of 1.5 to 50 μM and 25 to 200 μM coupled with the lower detection limits of 2.3 and 12.6 μM for isoniazid and hydrazine, respectively. The excellent analytical performance mainly results from the synergistic catalytic effect of the multiple metals and distinctive ultra-thin nanowires. This work provides a simple and rapid colorimetric method for the determination of isoniazid and hydrazine in actual samples.