Luminescent mesoporous nanorods as photocatalytic enzyme-like peroxidase surrogates

Abstract

One-step synthesis of luminescent mesoporous rods with enhanced photocatalytic response as novel metal-free peroxidase-like nanozymes.

Gold-Based Nanoparticles on Amino-Functionalized Mesoporous Silica Supports as Nanozymes for Glucose Oxidation

“…To quantify the glucose-oxidase enzyme mimicking activity of the Au-MCM-41 nanocatalyst, a kinetic study of the glucose conversion into gluconic acid was carried out. The kinetic parameters were determined after performing a series of experiments with increasing concentrations of glucose ( Figure 5a) and adjusting the gluconic acid generated after 30 min of reaction by quantitative colorimetric assays that included pH titration [50,71] and UV-Vis spectroscopy [70,72] (see Experimental section for further details). The data were fitted to a non-linear regression of the Michaelis-Menten equation and the apparent kinetic parameters were obtained using the Lineweaver-Burk double reciprocal plot as previously suggested by Gao et al [73] (see inset in Figure 5a).…”

“…The pH of the reaction mixture was held constant at 7.4. The kinetics of the catalytic reaction could be well adjusted to a typical Michaelis-Menten curve [70,72]. The Michaelis-Menten constant was calculated using the Lineweaver-Burk plot:…”

“…Finally, 62.5 µL of solution 3 (1 mol/L HCl, 0.1 mol/L FeCl 3 , and 0.25 mol/L CCl 3 COOH in water) was added to the reaction medium, and reaction was incubated for another 5 min before spectral acquisition. Absorbance values from the Fe-complex at different reaction times and total gluconic acid concentrations were correlated using the Lambert-Beer law and a molar absorption coefficient of 61.2 [50,[70][71][72]. In order to prevent the influence of the nanoparticles, the suspensions were previously centrifuged at 6000 rpm in 2 mL Eppendorfs.…”

“…Hydrogen peroxide (H 2 O 2 ) was indirectly tested with the aid of a horseradish peroxidase (HRP) enzyme that selectively favored the reduction of the H 2 O 2 present in solution and the simultaneous oxidation of ABTS or TMB with specific absorbances at 415 and 652 nm, respectively [12,70,72]. In a standard procedure, 300 µL of the filtered catalytic reaction solution was added to 50 µL of 8 mM ABTS and 50 µL of 0.4 µg/mL HRP.…”

Laser-driven direct synthesis of carbon nanodots and application as sensitizers for visible-light photocatalysis

“…The generation of hydroxyl radical under white LED irradiation was evaluated using terephtalic acid (TA) as a probe, which selectively reacts with •OH to form a fluorescent derivative [35,78,83]. In a typical procedure, the detection of hydroxyl radicals (…”