Alginate-based hydrogels embedded with ZnO nanoparticles as highly responsive colorimetric oxygen indicators
Issued Date
2022-09-22
Resource Type
ISSN
11440546
eISSN
13699261
Scopus ID
2-s2.0-85140458894
Journal Title
New Journal of Chemistry
Volume
46
Issue
40
Start Page
19322
End Page
19334
Rights Holder(s)
SCOPUS
Bibliographic Citation
New Journal of Chemistry Vol.46 No.40 (2022) , 19322-19334
Suggested Citation
Sattayapanich K., Chaiwat W., Boonmark S., Bureekaew S., Sutthasupa S. Alginate-based hydrogels embedded with ZnO nanoparticles as highly responsive colorimetric oxygen indicators. New Journal of Chemistry Vol.46 No.40 (2022) , 19322-19334. 19334. doi:10.1039/d2nj04164b Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/84049
Title
Alginate-based hydrogels embedded with ZnO nanoparticles as highly responsive colorimetric oxygen indicators
Author's Affiliation
Other Contributor(s)
Abstract
A hydrogel-based colorimetric oxygen indicator that exhibits high photoreduction efficiency and fast oxygen response was produced by integrating ZnO nanoparticles and a redox dye into an alginate hydrogel matrix. We found that varying the ZnO and glycerol [external sacrificial electron donor (SED)] content significantly affected the swelling behavior and strength of the hydrogels. We also found that retained water molecules and glycerol in the hydrogel serve as good electron donors, whereas ZnO nanoparticles are effective photocatalysts that affect the decoloration. By irradiating the hydrogel with UV light for 20 min, the UV intensity can induce the acceleration of the ZnO nanoparticles, creating photogenerated pores that are captured by the SEDs. Consequently, the photogenerated electrons rapidly reduced methylene blue to leuco-methylene blue, causing a color change from blue to colorless. Utilizing their porous network structures that facilitate oxygen diffusion, the hydrogel-based oxygen indicators exhibit fast recoloration (∼3 min) under a continuous ambient air (20 vol% O2 in nitrogen gas) flow rate of 500 mL min−1. The repeatability performance was improved by glycerol, illustrating the role of the external SED in our hydrogel-based oxygen indicator. We believe that the current study highlights the potential for the development of stimuli-responsive hydrogels as colorimetric oxygen-sensing materials.