Nanoparticle-Based Assays of Antioxidant Activity

Abstract

The antioxidant power of several phenolic acids and related food samples is estimated from the generation and growth of gold nanoparticles. The intensity of the resulting particle plasmon absorption bands correlates well with the redox characteristics of these phenolic acids estimated from cyclic voltammetry experiments. The highest capacity of reducing gold(III) to gold nanoparticles corresponds to the highest antioxidant activity, consistent with the tendency of phenolic acids to donate electrons.

Phenolic Antioxidant Capacity: A Review of the State of the Art

“…Scampicchio proposed, in one of the irst works in the ield [42], the assessment of some phenolic compounds by the generation and growth of gold nanoparticles (AuNPs) from a gold solution (AuIII) in solution (HAuCl 4 ) by the generation of a sharp plasmon absorption band at 555 nm. The optical properties of the AuNPs correlate well with the reduction potential of phenolic acids, something that can be determined by voltimetric measurements, and this method is proposed to evaluate antioxidant capacity of pure compounds or their mixtures [6].…”

Direct Electrochemical Sensing and Detection of Natural Antioxidants and Antioxidant Capacity in Vitro Systems

“…Finally, an interesting contribution regarding the evaluation of antioxidant capacity using gold nanoparticles has been proposed [53]. The antioxidant capacity of several phenolic acids and related food samples was estimated from the generation and growth of gold nanoparticles.…”

Green Synthesis of Noble Metal (Au, Ag, Pt) Nanoparticles, Assisted by Plant-Extracts

“…For instance, gallic acid, a secondary metabolite present in plants like green tea that also has powerful antioxidant properties, has been successfully used to obtain water soluble Au and Ag nanostructures, and has proved to be an efficient capping agent of these noble-metal nanoparticles. [38,39] Addition of Camellia sinensis extract to aqueous HAuCl 4 solutions, at ambient temperature, quickly turned the initial yellowish solution into pink, grey-blue and pale violet, respectively (inset of figure 3a). In case of formation of silver nanoparticles, the solution turned from yellowish to bright yellow and to dark brown (inset of figure 3b).…”