Co4N Nanowires: Noble-Metal-Free Peroxidase Mimetic with Excellent Salt- and Temperature-Resistant Abilities

Compared to natural enzymes, nanomaterial-based artificial enzymes have attracted immense attention because of their high stability and cost-effectiveness. In this study, cobalt nitride (Co 4 N) as a noble-metal-free artificial enzyme exhibiting highly intrinsic peroxidase-like activity and good stability was reported. Kinetic studies revealed that the resultant Co 4 N nanowires (NWs) exhibited a stronger affinity for 3,3′,5,5′-tetramethylbenzidine (TMB) and H 2 O 2 than HRP. Compared to Co 3 O 4 NWs, Co 4 N NWs exhibited highly improved catalytic activities, with H 2 O 2 exhibiting an apparent K m approximately 2 orders of magnitude less than that of Co 3 O 4 . In particular, the peroxidase-like activity of Co 4 N was maintained well over a wide range of temperatures and ionic strength. A Co 4 N-based method was further developed for the detection of glucose with good sensitivity and reliability. Because of advantages such as easy storage, cost-effectiveness, high sensitivity, and outstanding stability, Co 4 N NWs demonstrate the potential for replacing noble-metal-based peroxidase mimetics in a wide range of promising applications.