Eco-Friendly Synthesis of SnO2-Cu Nanocomposites and Evaluation of Their Peroxidase Mimetic Activity

Abstract

The enzyme mimetic activity of nanomaterials has been applied in colorimetric assays and point-of-care diagnostics. Several nanomaterials have been exploited for their peroxidase mimetic activity toward 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of hydrogen peroxide. However, an efficient nanomaterial for the rapid and strong oxidation of TMB remains a strategic challenge. Therefore, in this study, we developed copper-loaded tin oxide (SnO2-Cu) nanocomposites that rapidly oxidize TMB. These nanocomposites have strong absorption at 650 nm and can be used for highly sensitive colorimetric detection. An environmentally friendly (green), rapid, easy, and cost-effective method was developed for the synthesis of these nanocomposites, which were characterized using ultraviolet-visible, energy-dispersive X-ray, and Fourier-transform infrared spectroscopy, as well as scanning electron microscopy. This is the first green synthesis of SnO2-Cu nanocomposites. Their enzyme mimetic activity, which was first studied here, was found to be strongly dependent on the temperature and pH value of the solution. The synthesized nanocomposites have the advantages of low cost, high stability, and ease of preparation for enzyme mimetic applications. Hence, SnO2-Cu nanocomposites are a promising alternative to peroxidase enzymes in colorimetric point-of-care diagnostics.

Ultrasensitive and selective colorimetric detection of uric acid using peroxidase mimetic activity of biogenic palladium nanoparticles

“…Our previous study suggested that various factors affected the activity of nanozymes such as pH, temperature, incubation time, and nanoparticle concentrations. [ 13 ] The assay was performed at various pH ranges from 2 to 6 and a strong intensity was observed at pH 5. The reaction temperature was also evaluated in the range 5–80°C and the suitable temperature found was 22°C.…”

“…Our previous study suggested that various factors affected the F I G U R E 3 Biogenic Pd NPs [22] : (a) selected-area electron diffraction pattern (EDX) shows the existence of rings corresponding to the crystalline nature of nanoparticles; (b) X-ray photoelectron shows the binding energy of zero-valent palladium; (c) energy-dispersive X-ray spectroscopy (EDX) showing the signal for elemental palladium activity of nanozymes such as pH, temperature, incubation time, and nanoparticle concentrations. [13] The assay was performed at various pH ranges from 2 to 6 and a strong intensity was observed at pH 5.…”

“…[11] Nanomaterials show promising peroxidase mimetic activity for catalytic conversion of a chromogenic substance such as 3,3 0 ,5,5 0tetramethylbenzidine. [11][12][13] The biomolecule conversions into products are achieved using enzyme catalysis. Although enzymes work under mild conditions to facilitate the reaction, chemical catalysts can effectively proceed with the reaction under harsh environments, such as high temperatures, extreme pH, high pressures, and organic solvents.…”

Advances in Sno₂-Based Nanomaterials for Photocatalysis, Supercapacitors, and Antibacterial Activities

“…The increased effectiveness of its practical applications may be due to the improved properties, such as increased surface area, chemical and thermal stability, increased surface activities or number of active surface sites, enhanced charge transfer processes, mechanical strength, reduced electron-hole recombination, etc. [21][22][23][24][25][26][27][28][29][30].…”