Acetylated Lignins: A Potential Bio-Sourced Photosensitizer

Nowadays, lignins are receiving an increasing interest from the scientific community. Indeed, this biopolymer, formerly considered a waste-product of the paper industry, appears today as an interesting oil equivalent in many fields. In this context, many chemical modifications of lignins have been presented to valorize this attractive feedstock. However, spectroscopic properties of these modified materials remain poorly studied, in particular their capacity to produce reactive oxygen species (ROS) under light irradiation. Thus, the purpose of this work is to monitor the production of singlet oxygen and superoxide anion under light irradiation of three different acetylated lignins. The results obtained show that those modified lignins can generate ROS levels, allowing to consider a use of these materials as photosensitizers for applications such as photodynamic treatments.