Sensitive colorimetric detection of ascorbic acid based on seed mediated growth of sodium alginate reduced/stabilized gold nanoparticles

Titilope John Jayeoye; Uraiwan Sirimahachai; Thitima Rujiralai

doi:10.1016/j.carbpol.2020.117376

Sensitive colorimetric detection of ascorbic acid based on seed mediated growth of sodium alginate reduced/stabilized gold nanoparticles

Carbohydr Polym. 2021 Mar 1:255:117376. doi: 10.1016/j.carbpol.2020.117376. Epub 2020 Nov 5.

Authors

Titilope John Jayeoye¹, Uraiwan Sirimahachai², Thitima Rujiralai³

Affiliations

¹ Center of Excellence for Innovation in Chemistry and Division of Physical Science, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, 90112, Thailand; Analytical Chemistry and Environment Research Unit, Faculty of Science and Technology, Prince of Songkla University, Pattani, 94000, Thailand; Department of Chemistry/Biochemistry/Molecular Biology, Alex-Ekwueme Federal University, Ndufu-Alike-Ikwo, Abakaliki, Ebonyi State, Nigeria.
² Center of Excellence for Innovation in Chemistry and Division of Physical Science, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, 90112, Thailand.
³ Center of Excellence for Innovation in Chemistry and Division of Physical Science, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, 90112, Thailand; Analytical Chemistry and Environment Research Unit, Faculty of Science and Technology, Prince of Songkla University, Pattani, 94000, Thailand. Electronic address: thitima.r@psu.ac.th.

PMID: 33436207
DOI: 10.1016/j.carbpol.2020.117376

Abstract

A sensitive detection strategy for ascorbic acid (AA), using sodium alginate reduced/stabilized gold nanoparticles (SA-AuNPs) as the optical probe, is reported. The SA-AuNPs were prepared by mixing gold salt and SA under stirring for 2 h at room temperature, without any further steps. The mixture was aged at 4 °C overnight, after which a faint-purple colloidal solution of SA-AuNPs was obtained. Characterization shows that the synthesis is incapable of reducing all Au³⁺ to Au°, but rather to mixture of Au°/Au⁺. The addition of AA to the SA-AuNPs probe reduced completely all Au⁺ to new AuNPs which were deposited on the pre-formed SA-AuNPs seed, leading to size increment and absorption spectra enhancement. The assay exhibited a good linearity between 12.5 and 150.0 μM AA and low limit of quantification of 11.2 μM. It was further used for AA quantitation in vitamin C injection and fruit juice with satisfactory accuracy and precision.

Keywords: Alginate; Ascorbic acid; Colorimetry; Fruit juice; Nanoparticles; Vitamin C.