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A novel cerium oxide nanoparticles-based colorimetric sensor using tetramethyl benzidine reagent for antioxidant
F Ayca Ozdemir Olgun1, Ayşem Üzer2, Birsen Demirata Ozturk1
1Department of Chemistry, Faculty of Science and Letters, Istanbul Technical University, 34469 Maslak, Istanbul, Turkey.
Talanta
|March 5, 2018
Summary
A new colorimetric sensor uses poly(acrylic acid) sodium salt-coated cerium oxide nanoparticles (CeO-NPs) for sensitive antioxidant activity (AOA) assays. This nanotechnology-based method offers improved sensitivity and selectivity compared to existing sensors.
Area of Science:
- Nanotechnology
- Analytical Chemistry
- Materials Science
Background:
- Nanoparticles of transition metal oxides, particularly nanoceria, are emerging tools for antioxidant activity (AOA) assays.
- Cerium oxide nanoparticles (CeO-NPs) exhibit tunable redox properties, acting as oxidants or antioxidants based on preparation and size.
- Existing colorimetric sensors for AOA often lack sensitivity and selectivity, and can be affected by sample matrices.
Purpose of the Study:
- To develop a novel, highly sensitive, and selective colorimetric sensor for antioxidant activity (AOA) assays.
- To utilize poly(acrylic acid) sodium salt (PAANa)-coated CeO-NPs for enhanced sensor performance.
- To validate the sensor's performance using various antioxidants and assess potential interferents.
Main Methods:
- Development of a colorimetric sensor employing poly(acrylic acid) sodium salt (PAANa)-coated cerium oxide nanoparticles (CeO-NPs).
- Utilized the oxidation of tetramethyl benzidine (TMB) by PAANa-coated CeO-NPs in a slightly acidic solution (pH 4.0).
- Quantified antioxidant activity by measuring the decrease in color intensity (absorbance) of the TMB charge-transfer complex.
Main Results:
- The PAANa-coated CeO-NPs sensor demonstrated high sensitivity, with a detection limit of 8.25 × 10-9 mol L-1 for quercetin.
- The sensor accurately determined trolox equivalent antioxidant capacities for both hydrophilic and lipophilic antioxidants, comparable to conventional assays.
- Potential interferents like glucose and organic acids did not significantly affect the AOA determination, indicating good selectivity.
Conclusions:
- The developed PAANa-coated CeO-NP sensor offers a sensitive and selective platform for colorimetric antioxidant activity (AOA) assays.
- The red-shifted measurement wavelength minimizes interference from plant pigments, enhancing applicability in complex samples.
- This nanotechnology-based approach provides a superior alternative to existing colorimetric sensors for AOA determination.
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