Chitosan–Agar Biopolymer Nanocomposites with Ag and Zr-Doped ZnO: A Comprehensive Review of Synthesis, Characterization, Functional Properties and Emerging Applications
Keywords:
Chitosan; Agar; Silver nanoparticles; Zr-doped ZnO; Biopolymer nanocomposite; Antimicrobial activity; Photocatalysis; Green synthesis; Active packaging; Sustainable nanomaterials..Abstract
The integration of naturally derived biopolymers with functional nanoparticles has emerged as an important strategy for developing sustainable and multifunctional materials. Chitosan and agar are particularly attractive because of their biodegradability, biocompatibility, film-forming ability and abundance of reactive functional groups. Silver (Ag) nanoparticles provide strong antimicrobial and antioxidant functionality, whereas zirconium-doped zinc oxide (Zr–ZnO) offers tunable optical, photocatalytic, electrochemical and antibacterial properties. This review discusses the scientific basis for developing chitosan–agar biopolymer nanocomposites containing Ag and Zr–ZnO, with emphasis on synthesis approaches, polymer–nanoparticle interactions, characterization, functional properties and emerging applications. Previous studies have demonstrated that chitosan and agar form compatible blended films and that Ag nanoparticles can be generated in situ within chitosan–agar matrices using a green approach, with chitosan acting as a stabilizing component and agar contributing to reduction of silver ions. Related agar–ZnO and chitosan–ZnO systems further demonstrate the ability of natural polysaccharide matrices to accommodate metal-oxide nanoparticles while modifying mechanical, barrier, optical and antimicrobial properties. Zr doping provides an additional route for tuning the physicochemical characteristics of ZnO, including defect chemistry, optical response, surface activity and photocatalytic performance. The review critically compares reported preparation and characterization approaches and highlights the potential complementary functions of Ag and Zr–ZnO within a chitosan–agar matrix. Literature-derived performance data demonstrate strong antimicrobial activity in Ag/ZnO-containing agarose-based films and substantial photocatalytic activity of Zr–ZnO nanoparticles. Potential applications include active food packaging, antimicrobial coatings, wound-care materials, environmental remediation and multifunctional biodegradable films. Challenges related to nanoparticle dispersion, loading optimization, release, mechanical stability, scalability and environmental safety are also discussed. The combination of renewable biopolymers with Ag and Zr–ZnO represents a promising platform for the development of sustainable multifunctional nanocomposites...
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References
1. Elhefian, E.A., Nasef, M.M. and Yahaya, A.H. (2012). Preparation and characterization of chitosan/agar blended films: Part 1. Chemical structure and morphology. Journal of Chemistry, 2012, Article 840956.
2. Elhefian, E.A., Nasef, M.M. and Yahaya, A.H. (2012). Preparation and characterization of chitosan/agar blended films: Part 2. Thermal, mechanical, and surface properties. Journal of Chemistry, 2012, Article 285318. https://doi.org/10.1155/2012/285318.
3. Shi, D., Karmakar, B., Osman, H.E.H., El-kott, A.F., Morsy, K. and Abdel-Daim, M.M. (2022). Design and synthesis of chitosan/agar/Ag NPs: A potent and green bio-nanocomposite for the treatment of glucocorticoid induced osteoporosis in rats. Arabian Journal of Chemistry, 15(1), 103471. https://doi.org/10.1016/j.arabjc.2021.103471.
4. Balalakshmi, C., Alharbi, N.S., Kadaikunnan, S., Khaled, J.M., Alanzi, K.F., Gopinath, K., Arumugam, A. and Govindarajan, M. (2020). Development of chitosan/agar-silver nanoparticles-coated paper for antibacterial application. Green Processing and Synthesis, 9(1), 751–759. https://doi.org/10.1515/gps-2020-0070.
5. Li, W., Huang, Z., Cai, R., Yang, W., He, H. and Wang, Y. (2021). Rational design of Ag/ZnO hybrid nanoparticles on sericin/agarose composite film for enhanced antimicrobial applications. International Journal of Molecular Sciences, 22(1), 105. https://doi.org/10.3390/ijms22010105.
6. Kumar, S., Boro, J.C., Ray, D., Mukherjee, A. and Dutta, J. (2019). Bionanocomposite films of agar incorporated with ZnO nanoparticles as an active packaging material for shelf-life extension of green grape. Heliyon, 5(6), e01867. https://doi.org/10.1016/j.heliyon.2019.e01867.
7. Zhang, X., Zhang, Z., Wu, W., Yang, J. and Yang, Q. (2021). Preparation and characterization of chitosan/nano-ZnO composite film with antimicrobial activity. Bioprocess and Biosystems Engineering, 44, 1193–1199. https://doi.org/10.1007/s00449-021-02521-x.
8. Preparation and characterization of chitosan–nano-ZnO composite films for preservation of cherry tomatoes (2022). Foods. The study reported improved mechanical and antimicrobial performance with increasing nano-ZnO loading.
9. Raghupathi, K.R., Koodali, R.T. and Manna, A.C. (2011). Size-dependent bacterial growth inhibition and mechanism of antibacterial activity of zinc oxide nanoparticles. Langmuir, 27(7), 4020–4028.
10. Rabea, E.I., Badawy, M.E.-T., Stevens, C.V., Smagghe, G. and Steurbaut, W. (2003). Chitosan as antimicrobial agent: Applications and mode of action. Biomacromolecules, 4, 1457–1465.
11. Rai, M., Yadav, A. and Gade, A. (2009). Silver nanoparticles as a new generation of antimicrobials. Biotechnology Advances, 27, 76–83.
12. Zhang, X., Yang, J., Wu, W. and others (2015). Applications of chitosan powder with in situ synthesized nano-ZnO particles as an antimicrobial agent. International Journal of Biological Macromolecules.
13. Li, Y., et al. (2012). Characterisation and cooperative antimicrobial properties of chitosan/nano-ZnO composite nanofibrous membranes. Food Chemistry.
14. Physicochemical and functional properties of chitosan-based nano-composite films incorporated with biogenic silver nanoparticles (2019). Carbohydrate Polymers, 211, 124–132. https://doi.org/10.1016/j.carbpol.2019.02.005.
15. A novel green one-step synthesis of silver nanoparticles using chitosan: Catalytic activity and antimicrobial studies (2013). Applied Nanoscience.
16. Khan, Z. and Al-Thabaiti, S.A. (2022). Chitosan capped silver nanoparticles: Adsorption and photochemical activities. Arabian Journal of Chemistry, 15(11), 104154. https://doi.org/10.1016/j.arabjc.2022.104154.
17. Naik, E.I., Naik, H.B., Viswanath, R., Kirthan, B. and others (2020). Effect of zirconium doping on the structural, optical, electrochemical and antibacterial properties of ZnO nanoparticles prepared by sol-gel method. Chemical Data Collections, 29, 100505. https://doi.org/10.1016/j.cdc.2020.100505.
18. Dadvar, M., et al. (2022). Photocatalytic degradation of water disinfection by-products using zirconium doped zinc oxide nanoparticles. Desalination and Water Treatment, 252, 339–347. https://doi.org/10.5004/dwt.2022.28267.
19. Akhtar, H., Alhamoudi, F.H., Marshall, J., Ashton, T.E., Darr, J.A., Rehman, I.U., Chaudhry, A.A. and Reilly, G. (2024). Synthesis of cerium, zirconium, and copper doped zinc oxide nanoparticles as potential biomaterials for tissue engineering applications. Heliyon, 10(7), e29150.
20. Zr-modified ZnO nanoparticles: Optimized photocatalytic degradation and antibacterial efficiency for pollution control (2025). Ceramics International, 51(17), 23003–23020.
21. Özgür, Ü., Alivov, Y.I., Liu, C., Teke, A., Reshchikov, M.A., Doğan, S., Avrutin, V., Cho, S.J. and Morkoç, H. (2005). A comprehensive review of ZnO materials and devices. Journal of Applied Physics, 98, 041301.
22. Janotti, A. and Van de Walle, C.G. (2009). Fundamentals of zinc oxide as a semiconductor. Reports on Progress in Physics, 72, 126501.
23. Wang, Z.L. (2004). Zinc oxide nanostructures: Growth, properties and applications. Journal of Physics: Condensed Matter, 16, R829–R858.
24. Sirelkhatim, A., Mahmud, S., Seeni, A., Kaus, N.H.M., Ann, L.C., Bakhori, S.K.M., Hasan, H. and Mohamad, D. (2015). Review on zinc oxide nanoparticles: Antibacterial activity and toxicity mechanism. Nano-Micro Letters, 7, 219–242.
25. Espitia, P.J.P., Soares, N.F.F., Coimbra, J.S.R., de Andrade, N.J., Cruz, R.S. and Medeiros, E.A.A. (2012). Zinc oxide nanoparticles: Synthesis, antimicrobial activity and food packaging applications. Food and Bioprocess Technology, 5, 1447–1464.
26. Dutta, J. and Hofmann, H. (2005). Nanoparticles in biological applications. In: Encyclopedia of Nanoscience and Nanotechnology. American Scientific Publishers.
27. Rhim, J.W., Hong, S.I., Park, H.M. and Ng, P.K.W. (2006). Preparation and characterization of chitosan-based nanocomposite films with antimicrobial activity. Journal of Agricultural and Food Chemistry.
28. Aider, M. (2010). Chitosan application as a novel polyelectrolyte in the development of edible films and coatings. Food Science and Technology, 43, 837–842.
29. Aranberri, I., Bouchal, R., Green, R.J., Douroumis, D. and others (2017). Recent advances in the design and characterization of nanocomposites based on chitosan and inorganic nanoparticles. Carbohydrate Polymers.
30. Yadav, A., Prasad, V., Kathe, A.A., Padmanabhan, S., Vardan, R. and Yadav, N. (2008). Functional finishing in cotton fabrics using zinc oxide nanoparticles. Bulletin of Materials Science, 31, 205–211.
31. Shapi'i, R.A., Othman, S.H., Nordin, N., Basha, R.K. and Tawakkal, I.S.M.A. (2022). Antimicrobial properties of starch/chitosan films incorporated with ZnO nanoparticles. Nanomaterials.
32. Shapi'i, R.A., Othman, S.H., Nordin, N., Basha, R.K. and Tawakkal, I.S.M.A. (2022). Characterization and antimicrobial properties of biopolymer-based nanocomposite films containing metal-oxide nanoparticles. Polymers.
33. Sondi, I. and Salopek-Sondi, B. (2004). Silver nanoparticles as antimicrobial agent: A case study on E. coli as a model for Gram-negative bacteria. Journal of Colloid and Interface Science, 275, 177–182.
34. Morones, J.R., Elechiguerra, J.L., Camacho, A., Holt, K., Kouri, J.B., Ramírez, J.T. and Yacaman, M.J. (2005). The bactericidal effect of silver nanoparticles. Nanotechnology, 16, 2346–2353.
35. Stoimenov, P.K., Klinger, R.L., Marchin, G.L. and Klabunde, K.J. (2002). Metal oxide nanoparticles as bactericidal agents. Langmuir, 18, 6679–6686.
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