The application of thymol-loaded chitosan nanoparticles to control the biodeterioration of cultural heritage sites

Biocides are widely used to impede the growth of harmful microorganisms, whose colonization will cause biodeterioration of cultural heritage sites. However, frequent application of biocides is costly and hazardous to both humans and the environment. In this study, a series of thymol-loaded chitosan nanoparticles were prepared by the emulsification-ionic gelation method and verified by instrumental analytical techniques (UV-Vis spectrophotometry, SEM/TEM, FTIR, and TGA/DTG). The results show that thymol is encapsulated within chitosan nanoparticles, thus the release of the natural biocides can be controlled. Compared with free thymol, thymol-loaded chitosan nanoparticles demonstrate a better performance against Aspergillus niger, a class of fungus isolated from the Feilaifeng limestone. This novel strategy could be applied to the preservation and protection of outdoor stone-built cultural heritage sites to reduce the amount and frequency of biocides application. (c) 2021 Elsevier Masson SAS. All rights reserved.

Automated summary

Thymol-loaded chitosan nanoparticles were successfully prepared and verified to control the release of natural biocides. These nanoparticles showed better performance against Aspergillus niger compared to free thymol, offering a novel approach to reduce the amount and frequency of biocides application for the preservation of outdoor stone-built cultural heritage sites.