Jump to main content
Jump to site search


A manganese oxide (MnOx)-Based colorimetric nanosensor for indirect measurement of lipophilic and hydrophilic antioxidant capacity

Author affiliations

Abstract

Nanomaterials and composites containing metal oxides are increasingly being used in human health, cosmetics and food packaging applications, which may give rise to the evolution of reactive species on nanosurfaces by autoxidation with air O2. In recent years, novel analytical approaches have been developed for total antioxidant capacity (TAC) determination, with special emphasis on nanoparticle-based sensors due to their low cost, easy use, rapid response and high precision. A nano-manganese oxide (nano-MnOx)-based spectrophotometric method was developed for the indirect capacity measurement of antioxidant compounds, based on the measurement of the decrease in the color intensity (at λmax = 650 nm) of 3,3′,5,5′-tetramethylbenzidine cations (TMB+) in the presence of hydrophilic and lipophilic antioxidants. TMB+ cations were obtained via a redox reaction between MnOx NPs and the TMB chromophore in open air, and antioxidants caused a decrease of TMB+ color intensity. MnOx NPs could be easily and rapidly prepared at low cost. The linearity, repeatability and recovery parameters defining reliability and precision were tested to validate the sensing method. Depending on the type of tested antioxidant, the limit of detection (LOD) values were in the range of 1.23 × 10−9 to 1.71 × 10−7 mol L−1. The developed nanoprobe was applied to ternary synthetic mixtures of antioxidants to yield expected and found TAC values (as trolox-equivalents) in agreement. The potential interferents such as benzoic acid, citric acid, glucose and mannitol did not adversely affect the TAC determination. To test real samples, the method of standard addition of pure antioxidant compounds was applied to real samples such as green tea and orange juice.

Graphical abstract: A manganese oxide (MnOx)-Based colorimetric nanosensor for indirect measurement of lipophilic and hydrophilic antioxidant capacity

Back to tab navigation

Supplementary files

Article information


Submitted
18 Sep 2019
Accepted
06 Nov 2019
First published
19 Dec 2019

Anal. Methods, 2020, Advance Article
Article type
Paper

A manganese oxide (MnOx)-Based colorimetric nanosensor for indirect measurement of lipophilic and hydrophilic antioxidant capacity

K. Can, A. Üzer and R. Apak, Anal. Methods, 2020, Advance Article , DOI: 10.1039/C9AY02027F

Social activity

Search articles by author

Spotlight

Advertisements