Real-time colorimetric detection of dissolved carbon dioxide using pH-sensitive indicator based on anthocyanin and PVA coated green iron oxide nanoparticles at room temperature

Abstract

In this study, a pH-sensitive indicator solution for the colorimetric naked-eye detection of dissolved carbon dioxide at room temperature was developed with the aim of environmental monitoring. The indicator solution was produced by the polyvinyl alcohol-coated green synthesized iron oxide nanoparticles and the natural anthocyanin extracted from red cabbage. The pH change upon carbon dioxide dissociation occurred in the indicator solution. The reaction was investigated using the stopped-flow method by monitoring the pH measurements at different dissolved CO₂ concentrations. The indicator solution changed color from blue to pink within a few seconds with pH change on the acidic side and returned to its initial state spontaneously without any treatment at the end of the CO₂ gas. The indicator solution showed sensitivity to dissolved CO₂ concentrations in the range of 600 − 3200 ppm in a fast reaction time and complete reversibility.

Keywords:

• Dissolved carbon dioxide
• colorimetric monitoring
• PVA
• anthocyanin
• iron oxide Nanoparticles

Acknowledgements

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Disclosure statement

There are no conflicts to declare.

Credit author statement

Derya Aksu Demirezen: Methodology, Data Curation, Investigation, Writing – Editing Dilek Demirezen Yılmaz: Resources