Encapsulation of environmentally-friendly biocides in silica nanosystems for multifunctional coatings

•Design of new environmentally-friendly fillers for innovative multifunctional coatings.•Successful encapsulation of usnic acid and zosteric acid sodium salt in two silica nanosystems.•Antifouling tests of the nanosystems against microorganisms from biological patinas colonising the Aurelian Walls in Rome.