The increasing number of microbial infections and antibiotic resistance has led to the emergence need to develop innovative
nanomaterials with effective antimicrobial activity. The chitosan-based nanocomposites have shown interesting properties
with potential antimicrobial activity. This study synthesized a hetero-photocatalyst composite by solution casting,
combining chitosan with a hybrid material of carbon nanodots (CNDs) and zinc oxide nanoparticles (ZnO). CNDs was
derived from olive solid waste using pyrolysis and were mixed and hybridized with ZnO via sol-gel methods. Then, the
CNDs/ZnO hybrid was mixed and incorporated into a pale tan, transparent chitosan film to obtain chitosan-hybrid. The
composite exhibited enhanced absorption intensity with peaks between 207 and 229 nm and at 289 nm, with a tail extending
into the visible range. Atomic force microscopy (AFM) revealed the heterogeneous distribution of hybrid materials
forming pineapple rings like shape within the chitosan matrix. Antimicrobial activity tests were also performed against
various microbial strains (Staphylococcus aureus, Klebsiella pneumonia, Escherichia coli, methicillin-resistant Staphylococcus
aureus (MRSA), Saccharomyces cerevisiae, Proteus vulgaris, and Aspergillus fumigates) under both dark and visible
light modes. The Chitosan-Hybrid exhibited notable antimicrobial activity in the presence of photo-light irradiation,
with a minimal inhibitory concentration range (1.95–15.6) μg/L, a 99.99% growth inhibition, and the killing time kinetic
of 25 min to 1:15 h. The glutathione oxidation test and the ROS scavengers experiments confirmed that the antimicrobial
activity stemmed from the composite’s ability to generate reactive oxygen species under photo-light irradiation, with a
glutathione deficiency oxidation rate of 96.8%. These findings highlight the composite potential as an eco-friendly, effective
antimicrobial agent for diverse applications.

Title

BioNanoScience

Publisher

Springer Nature

Publisher Country

United Kingdom

Indexing

Thomson Reuters

Impact Factor

4.0

Publication Type

Both (Printed and Online)

Volume

16

Year

2026

Pages

--