Mimicking Horseradish Peroxidase Functions Using Cu2+-Modified Carbon Nitride Nanoparticles or Cu2+-Modified Carbon Dots as Heterogeneous Catalysts

Cu2+-functionalized carbon nitride nanoparticles (Cu2+–g-C3N4 NPs), ∼200 nm, and Cu2+–carbon dots (Cu2+–C-dots), ∼8 nm, act as horseradish peroxidase-mimicking catalysts. The nanoparticles catalyze the generation of chemiluminescence in the presence of luminol/H2O2 and catalyze the oxidation of dopamine by H2O2 to form aminochrome. The Cu2+–g-C3N4-driven generation of chemiluminescence is used to develop a H2O2 sensor and is implemented to develop a glucose detection platform and a sensor for probing glucose oxidase. Also, the Cu2+–C-dots are functionalized with the β-cyclodextrin (β-CD) receptor units. The concentration of dopamine, at the Cu2+–C-dots' surface, by means of the β-CD receptor sites, leads to a 4-fold enhancement in the oxidation of dopamine by H2O2 to yield aminochrome compared to that of the unmodified C-dots.