triple-enzymatic activity of cumn2o4 nanoparticles: analytical applications for h2o2 and l-cysteine detection

Cumn2o4 nps were prepared via coprecipitation method and characterized using microscopic and spectroscopic analyses. cumn2o4 nps exhibit a triple-enzymatic activity including peroxidase-, oxidase- and catalase-like activity. the effect of various parameters on the initial rate of the catalytic reaction of cumn2o4 nps with peroxidase- and oxidase-like activity was studied by uv-vis spectrometer following the increasing absorption at 415 nm corresponding to the oxidation product of substrate o-phenylenediamine (opd). kinetic analyses indicate the michaelis-menten model for cumn2o4 nps for both peroxidase- and oxidase-like activity. based on the high peroxidase-like activity of cumn2o4 nps, they were further studied as a colorimetric sensor for the detection of h2o2 with a linear range from 0.5 mm to 22 mm and detection limit of 0.11 mm. inhibition of the high oxidase-like activity of cumn2o4 nps was utilized for colorimetric detection of l-cysteine with a linear range from 50 µm to 200 µm and a detection limit of 54.15 µm.