Green Synthesis of Metal and Metal Oxide Nanoparticles Mediated by Plant Extracts

Abstract

This study focuses on the biogenic synthesis of metal and metal oxide nanoparticles (NPs) specifically mediated by plant extracts, highlighting this approach as a rapid, cost-effective, and eco-friendly alternative to traditional methods. While nanotechnology enables the engineering of materials with high surface-to-volume ratios, the environmental risks associated with chemical reagents have shifted research interest toward green synthesis. In this process, the secondary metabolites inherent in plant extracts-such as alkaloids, flavonoids, phenolic acids, saponins, and terpenoids-function as potent natural reducing and capping agents. These phytochemicals facilitate the biochemical reduction of metal ions into stable nanoparticles through a three-phase mechanism: activation, thermodynamic stabilization, and termination. The study details how extracts from various plant parts (leaves, roots, fruits, and seeds) enable the controlled production of Ag, Au, ZnO, and CuO NPs with distinct morphological and functional properties. Advanced characterization tools, including XRD, FTIR, UV-Vis, SEM, and TEM, are utilized to elucidate the structural integrity and size distribution of these biogenic NPs. Furthermore, the evaluation of biosafety highlights that while these NPs offer high biocompatibility, their efficacy and cytotoxicity must be balanced through precise dose optimization. Ultimately, plant-mediated synthesis represents a sustainable paradigm for producing high-purity nanoparticles with robust biological and catalytic activities.

Keywords

• Green synthesis
• Metal/Metal Oxide nanoparticles
• Phytochemicals
• Plant extracts

Supporting Institution

This research received no external funding.

Ethical Statement

This study does not involve human or animal participants. All procedures were performed in accordance with scientific and ethical principles, and all cited works have been appropriately referenced.

Thanks

This study is derived from a part of author's doctoral thesis.

Bitki Ekstraktları Aracılığıyla Metal ve Metal Oksit Nanopartiküllerin Yeşil Sentezi

Abstract

Bu çalışma, metal ve metal oksit nanopartiküllerin (NP) özellikle bitki ekstraktları aracılığıyla gerçekleştirilen biyojenik sentezine odaklanmakta; bu yaklaşımı geleneksel yöntemlere karşı hızlı, ekonomik ve çevre dostu bir alternatif olarak sunmaktadır. Nanoteknoloji, yüksek yüzey/hacim oranına sahip malzemelerin mühendisliğine imkan tanırken, kimyasal reaktiflerin çevresel riskleri, araştırma ilgisini yeşil senteze yöneltmiştir. Bu süreçte; bitki özütlerinde doğal olarak bulunan alkaloidler, flavonoidler, fenolik asitler, saponinler ve terpenoidler gibi ikincil metabolitler, güçlü doğal indirgeme ve kaplama ajanları olarak işlev görmektedir. Bu fitokimyasallar, metal iyonlarının kararlı nanopartiküllere biyokimyasal dönüşümünü; aktivasyon, termodinamik stabilizasyon ve sonlanma aşamalarından oluşan üç fazlı bir mekanizma ile gerçekleştirmektedir. Çalışma; yaprak, kök, meyve ve tohum gibi farklı bitki kısımlarından elde edilen ekstraktların Ag, Au, ZnO ve CuO gibi NP’lerin kontrollü üretimine nasıl olanak tanıdığını detaylandırmaktadır. Biyojenik NP’lerin yapısal bütünlüğünü ve boyut dağılımını belirlemek amacıyla XRD, FTIR, UV-Vis, SEM ve TEM gibi ileri karakterizasyon araçlarından yararlanılmaktadır. Ayrıca biyogüvenlik değerlendirmeleri, bu NP’lerin yüksek biyouyumluluk sunmasına rağmen, etkinlik ve sitotoksisite dengesinin hassas doz optimizasyonu ile korunması gerektiğini vurgulamaktadır. Sonuç olarak bitki aracılı sentez, güçlü biyolojik ve katalitik aktiviteye sahip yüksek saflıkta nanopartiküller üretmek için sürdürülebilir bir paradigma teşkil etmektedir.

Keywords

• Bitki ekstraktları
• Fitokimyasallar
• Metal/Metal oksit nanopartiküller
• Yeşil sentez

References

1. Adeyemi, J. O., Onwudiwe, D. C., & Oyedeji, A. O. (2022). Biogenic synthesis of CuO, ZnO, and CuO–ZnO nanoparticles using leaf extracts of Dovyalis caffra and their biological properties. Molecules, 27(10), Article 3206. https://doi.org/10.3390/molecules27103206
2. Ahmad, N. M., Mohamed, A. H., Hasan, N. A., Zainal-Abidin, N., Zaini Nawahwi, M., & Mohamad Azzeme, A. (2024). Effect of optimisation variable and the role of plant extract in the synthesis of nanoparticles using plant-mediated synthesis approaches. Inorganic Chemistry Communications, 161, Article 111839. https://doi.org/10.1016/j.inoche.2023.111839
3. Ahmadi, A., Mirzaeizadeh, Z., & Omidfar, K. (2021). Simultaneous detection of SARS-CoV-2 IgG/IgM antibodies, using gold nanoparticles-based lateral flow immunoassay. Monoclonal Antibodies in Immunodiagnosis & Immunotherapy, 40(5), 210–218. https://doi.org/10.1089/mab.2021.0027
4. Alam, M. A., Ahmed, S., Bishwas, R. K., Mostofa, S., & Jahan, S. A. (2025). X-ray crystallographic diffraction study by whole powder pattern fitting (WPPF) method: Refinement of crystalline nanostructure polymorphs TiO2. South African Journal of Chemical Engineering, 51, 68–77. https://doi.org/10.1016/j.sajce.2024.10.010
5. Alameen, A. S., Undre, S. B., & Undre, P. B. (2024). Synthesis, dispersion, functionalization, biological and antioxidant activity of metal oxide nanoparticles: Review. Nano-Structures & Nano-Objects, 39, Article 101298. https://doi.org/10.1016/j.nanoso.2024.101298
6. Ali, A., Aasim, M., Çelik, K., Nadeem, M. A., & Baloch, F. S. (2024). Frontiers in bacterial-based green synthesized nanoparticles (NPs): A sustainable strategy for combating infectious plant pathogens. Biocatalysis and Agricultural Biotechnology, 60, Article 103293. https://doi.org/10.1016/j.bcab.2024.103293
7. Andreescu, S., Ornatska, M., Erlichman, J. S., Estevez, A., & Leiter, J. C. (2012). Biomedical applications of metal oxide nanoparticles. In E. Matijević (Ed.), Fine particles in medicine and pharmacy (pp. 57–100). Springer. https://doi.org/10.1007/978-1-4614-0379-1_3
8. Anyaogu, K. C., Fedorov, A. V., & Neckers, D. C. (2008). Synthesis, characterization, and antifouling potential of functionalized copper nanoparticles. Langmuir, 24(8), 4340–4346. https://doi.org/10.1021/la800102f

9. Ashraf, S. A., Siddiqui, A. J., Elkhalifa, A. E. O., Khan, M. I., Patel, M., Alreshidi, M., Moin, A., Singh, R., Snoussi, M., & Adnan, M. (2021). Innovations in nanoscience for the sustainable development of food and agriculture with implications on health and environment. Science of the Total Environment, 768, Article 144990. https://doi.org/10.1016/j.scitotenv.2021.144990
10. Badri, A., Slimi, S., Guergueb, M., Kahri, H., & Mateos, X. (2021). Green synthesis of copper oxide nanoparticles using prickly pear peel fruit extract: Characterization and catalytic activity. Inorganic Chemistry Communications, 134, Article 109027. https://doi.org/10.1016/j.inoche.2021.109027
11. Baldassarre, F., Cacciola, M., & Ciccarella, G. (2015). A predictive model of iron oxide nanoparticles flocculation tuning Z-potential in aqueous environment for biological application. Journal of Nanoparticle Research, 17(9), Article 377. https://doi.org/10.1007/s11051-015-3163-6
12. Banik, B. L., Fattahi, P., & Brown, J. L. (2016). Polymeric nanoparticles: The future of nanomedicine. Wiley Interdisciplinary Reviews: Nanomedicine and Nanobiotechnology, 8(2), 271–299. https://doi.org/10.1002/wnan.1364
13. Behzad, F., Naghib, S. M., Kouhbanani, M. A. J., Tabatabaei, S. N., Zare, Y., & Rhee, K. Y. (2021). An overview of the plant-mediated green synthesis of noble metal nanoparticles for antibacterial applications. Journal of Industrial and Engineering Chemistry, 94, 92–104. https://doi.org/10.1016/j.jiec.2020.12.005
14. Cengiz, M., Gür, B., Sezer, C. V., Baytar, O., Şahin, Ö., Ayhanci, A., & Kutlu, H. M. (2024). Green biosynthesis of selenium and zinc oxide nanoparticles using whole plant extract of Rheum ribes: Characterization, anticancer, and antimicrobial activity. Journal of Molecular Liquids, 412, Article 125861. https://doi.org/10.1016/j.molliq.2024.125861
15. Chandrakala, V., Aruna, V., & Angajala, G. (2022). Review on metal nanoparticles as nanocarriers: Current challenges and perspectives in drug delivery systems. Emergent Materials, 5(6), 1593–1615. https://doi.org/10.1007/s42247-021-00335-x
16. Chang, X., Wang, Y. F., Zhang, X., Liu, Z., Fu, J., Zhao, D., Fan, S., Bu, R., Zhang, J., Wang, W., & Wang, H. X. (2019). Enhanced ultraviolet absorption in diamond surface via localized surface plasmon resonance in palladium nanoparticles. Applied Surface Science, 464, 455–457. https://doi.org/10.1016/j.apsusc.2018.09.087
17. Cheng, Q., & Liu, Y. (2017). Multifunctional platinum-based nanoparticles for biomedical applications. Wiley Interdisciplinary Reviews: Nanomedicine and Nanobiotechnology, 9(2), e1410. https://doi.org/10.1002/wnan.1410
18. Dadhich, A., Jain, R., & Sharma, M. M. (2025). Bacopa monnieri (L.) Wettst. plant extract mediated synthesis of metallic nanoparticles and regulation of bacoside-A memory enhancer compound and their application: A comprehensive review. Plant Nano Biology, 11, Article 100133. https://doi.org/10.1016/j.plana.2024.100133
19. Ealia, S. A. M., & Saravanakumar, M. P. (2017). A review on the classification, characterisation, synthesis of nanoparticles and their application. IOP Conference Series: Materials Science and Engineering, 263(3), Article 032019. https://doi.org/10.1088/1757-899X/263/3/032019
20. Eker, F., Duman, H., Akdaşçi, E., Bolat, E., Sarıtaş, S., Karav, S., & Witkowska, A. M. (2024). A comprehensive review of nanoparticles: From classification to application and toxicity. Molecules, 29(15), Article 3482. https://doi.org/10.3390/molecules29153482
21. Fanoro, O. T., Parani, S., Maluleke, R., Lebepe, T. C., Varghese, J. R., Mavumengwana, V., & Oluwafemi, O. S. (2021). Facile green, room-temperature synthesis of gold nanoparticles using Combretum erythrophyllum leaf extract: Antibacterial and cell viability studies against normal and cancerous cells. Antibiotics, 10(8), Article 893. https://doi.org/10.3390/antibiotics10080893
22. Gatou, M. A., Skylla, E., Dourou, P., Pippa, N., Gazouli, M., Lagopati, N., & Pavlatou, E. A. (2024). Magnesium oxide (MgO) nanoparticles: Synthetic strategies and biomedical applications. Crystals, 14(3), Article 215. https://doi.org/10.3390/cryst14030215
23. Gokila, V., Perarasu, V. T., & Rufina, R. (2021). Qualitative comparison of chemical and green synthesized Fe3O4 nanoparticles. Advances in Nano Research, 10(1), 71–76.
24. Govindasamy, R., Govindarasu, M., Alharthi, S. S., Mani, P., Bernaurdshaw, N., Gomathi, T., Ansari, M. A., Alomary, M. N., Atwah, B., Malik, M. S., Rajeswari, V. D., Rekha, K., Ahmed, S. A., & Thiruvengadam, M. (2022). Sustainable green synthesis of yttrium oxide (Y2O3) nanoparticles using Lantana camara leaf extracts: Physicochemical characterization, photocatalytic degradation, antibacterial, and anticancer potency. Nanomaterials, 12(14), Article 2393. https://doi.org/10.3390/nano12142393
25. Groarke, R., Vijayaraghavan, R. K., Powell, D., Rennie, A., & Brabazon, D. (2021). Powder characterization—Methods, standards, and state of the art. In D. Gu, M. M. Attallah, M. Brandt, M. H. F. Sluiter, & Y. C. Hagedorn (Eds.), Fundamentals of laser powder bed fusion of metals (pp. 491–527). Elsevier. https://doi.org/10.1016/B978-0-12-824090-8.00006-8
26. Hillyer, M. B., Jordan, J. H., Ernst, N. E., Nam, S., & Easson, M. W. (2024). Cu2O/CuO nanoparticle-cotton fiber biocomposite catalyst: Self-improvement through morphological changes during methyl orange degradation. Langmuir, 40(52), 27174–27182. https://doi.org/10.1021/acs.langmuir.4c02405
27. Huston, M., Debella, M., Dibella, M., & Gupta, A. (2021). Green synthesis of nanomaterials. Nanomaterials, 11(8), Article 2130. https://doi.org/10.3390/nano11082130
28. Ijaz, I., Gilani, E., Nazir, A., & Bukhari, A. (2020). Detail review on chemical, physical and green synthesis, classification, characterizations and applications of nanoparticles. Green Chemistry Letters and Reviews, 13(3), 59–81. https://doi.org/10.1080/17518253.2020.1802517
29. Illath, K., Wankhar, S., Mohan, L., Nagai, M., & Santra, T. S. (2021). Metallic nanoparticles for biomedical applications. In T. S. Santra (Ed.), Nanomaterials and their biomedical applications (pp. 29–81). Springer. https://doi.org/10.1007/978-981-33-6252-9_2
30. Iravani, S. (2011). Green synthesis of metal nanoparticles using plants. Green Chemistry, 13(10), 2638–2650. https://doi.org/10.1039/c1gc15386b
31. Isaacoff, B. P., & Brown, K. A. (2017). Progress in top-down control of bottom-up assembly. Nano Letters, 17(11), 6508–6510. https://doi.org/10.1021/acs.nanolett.7b04479
32. Jadoun, S., Arif, R., Jangid, N. K., & Meena, R. K. (2021). Green synthesis of nanoparticles using plant extracts: A review. Environmental Chemistry Letters, 19(1), 355–374. https://doi.org/10.1007/s10311-020-01074-x
33. Joudeh, N., & Linke, D. (2022). Nanoparticle classification, physicochemical properties, characterization, and applications: A comprehensive review for biologists. Journal of Nanobiotechnology, 20, Article 262. https://doi.org/10.1186/s12951-022-01477-8
34. Kabeerdass, N., Murugesan, K., Arumugam, N., Almansour, A. I., Kumar, R. S., Djearamane, S., Kumaravel, A. K., Velmurugan, P., Mohanavel, V., Kumar, S. S., Vijayanand, S., Padmanabhan, P., Gulyás, B., & Mathanmohun, M. (2022). Biomedical and textile applications of Alternanthera sessilis leaf extract mediated synthesis of colloidal silver nanoparticle. Nanomaterials, 12(16), Article 2759. https://doi.org/10.3390/nano12162759
35. Khan, F., Shariq, M., Asif, M., Siddiqui, M. A., Malan, P., & Ahmad, F. (2022). Green nanotechnology: Plant-mediated nanoparticle synthesis and application. Nanomaterials, 12(4), Article 673. https://doi.org/10.3390/nano12040673
36. Khan, I., Saeed, K., & Khan, I. (2019). Nanoparticles: Properties, applications and toxicities. Arabian Journal of Chemistry, 12(7), 908–931. https://doi.org/10.1016/j.arabjc.2017.05.011
37. Khatami, M., Alijani, H. Q., Fakheri, B., Mobasseri, M. M., Heydarpour, M., Farahani, Z. K., & Khan, A. U. (2019). Super-paramagnetic iron oxide nanoparticles (SPIONs): Greener synthesis using Stevia plant and evaluation of its antioxidant properties. Journal of Cleaner Production, 208, 1171–1177. https://doi.org/10.1016/j.jclepro.2018.10.182
38. Klinavičius, T., Khinevich, N., Tamulevičienė, A., Vidal, L., Tamulevičius, S., & Tamulevičius, T. (2024). Deep learning methods for colloidal silver nanoparticle concentration and size distribution determination from UV-Vis extinction spectra. The Journal of Physical Chemistry C, 128(23), 9662–9675. https://doi.org/10.1021/acs.jpcc.4c02459
39. Kokorina, A. A., Ermakov, A. V., Abramova, A. M., Goryacheva, I. Y., & Sukhorukov, G. B. (2020). Carbon nanoparticles and materials on their basis. Colloids and Interfaces, 4(4), Article 42. https://doi.org/10.3390/colloids4040042
40. Krishnaraj, C., Muthukumaran, P., Ramachandran, R., Balakumaran, M. D., & Kalaichelvan, P. T. (2014). Acalypha indica Linn: Biogenic synthesis of silver and gold nanoparticles and their cytotoxic effects against MDA-MB-231 human breast cancer cells. Biotechnology Reports, 4(1), 42–49. https://doi.org/10.1016/j.btre.2014.08.002
41. Kumari, Y., Kaur, G., Kumar, R., Singh, S. K., Gulati, M., Khursheed, R., Clarisse, A., Gowthamarajan, K., Karri, V. V. S. N. R., Mahalingam, R., Ghosh, D., Awasthi, A., Kumar, R., Yadav, A. K., Kapoor, B., Singh, P. K., Dua, K., & Porwal, O. (2019). Gold nanoparticles: New routes across old boundaries. Advances in Colloid and Interface Science, 274, Article 102037. https://doi.org/10.1016/j.cis.2019.102037
42. Loganathan, S., Govindasamy, M., Habila, M. A., & Manimaran, K. (2023). Green synthesis of iron oxide nanoparticles using Pterolobium hexapetalum (Roth) Santapau & Wagh leaves extract and their biological applications. Biocatalysis and Agricultural Biotechnology, 54, Article 102905. https://doi.org/10.1016/j.bcab.2023.102905
43. Luzala, M. M., Muanga, C. K., Kyana, J., Safari, J. B., Zola, E. N., Mbusa, G. V., Nuapia, Y. B., Liesse, J. M. I., Nkanga, C. I., Krause, R. W. M., Balčiūnaitienė, A., & Memvanga, P. B. (2022). A critical review of the antimicrobial and antibiofilm activities of green-synthesized plant-based metallic nanoparticles. Nanomaterials, 12(11), Article 1841. https://doi.org/10.3390/nano12111841
44. Magdassi, S., Grouchko, M., & Kamyshny, A. (2010). Copper nanoparticles for printed electronics: Routes towards achieving oxidation stability. Materials, 3(9), 4626–4638. https://doi.org/10.3390/ma3094626
45. Maheswaran, H., Djearamane, S., Tanislaus Antony Dhanapal, A. C., & Wong, L. S. (2024). Cytotoxicity of green synthesized zinc oxide nanoparticles using Musa acuminata on Vero cells. Heliyon, 10(11), e31316. https://doi.org/10.1016/j.heliyon.2024.e31316
46. Makarov, V. V., Love, A. J., Sinitsyna, O. V., Makarova, S. S., Yaminsky, I. V., Taliansky, M. E., & Kalinina, N. O. (2014). “Green” nanotechnologies: Synthesis of metal nanoparticles using plants. Acta Naturae, 6(1), 35–44. https://doi.org/10.32607/20758251-2014-6-1-35-44
47. Malik, S., Muhammad, K., & Waheed, Y. (2023). Nanotechnology: A revolution in modern industry. Molecules, 28(2), Article 661. https://doi.org/10.3390/molecules28020661
48. McNamara, K., & Tofail, S. A. M. (2017). Nanoparticles in biomedical applications. Advances in Physics: X, 2(1), 54–88. https://doi.org/10.1080/23746149.2016.1254570
49. Miu, B. A., & Dinischiotu, A. (2022). New green approaches in nanoparticles synthesis: An overview. Molecules, 27(19), Article 6472. https://doi.org/10.3390/molecules27196472
50. Modena, M. M., Rühle, B., Burg, T. P., & Wuttke, S. (2019). Nanoparticle characterization: What to measure? Advanced Materials, 31(32), Article 1901556. https://doi.org/10.1002/adma.201901556
51. Moghaddam, A. B., Namvar, F., Moniri, M., Tahir, P. M., Azizi, S., & Mohamad, R. (2015). Nanoparticles biosynthesized by fungi and yeast: A review of their preparation, properties, and medical applications. Molecules, 20(9), 16540–16565. https://doi.org/10.3390/molecules200916540
52. Mourdikoudis, S., Pallares, R. M., & Thanh, N. T. K. (2018). Characterization techniques for nanoparticles: Comparison and complementarity upon studying nanoparticle properties. Nanoscale, 10(27), 12871–12934. https://doi.org/10.1039/c8nr02278j
53. Mukherjee, D., Sil, M., Goswami, A., Lahiri, D., & Nag, M. (2023). Antibiofilm activities of carbon-based nanoparticles and nanocomposites: A comparative review. Journal of Inorganic and Organometallic Polymers and Materials, 33(12), 3961–3983. https://doi.org/10.1007/s10904-023-02732-7
54. Murthy, S., Effiong, P., & Fei, C. C. (2020). Metal oxide nanoparticles in biomedical applications. In Metal oxide powder technologies: Fundamentals, processing methods and applications (pp. 233–251). Elsevier. https://doi.org/10.1016/B978-0-12-817505-7.00011-7
55. Mutukwa, D., Taziwa, R. T., Tichapondwa, S. M., & Khotseng, L. (2024). Optimisation, synthesis, and characterisation of ZnO nanoparticles using Leonotis ocymifolia leaf extracts for antibacterial and photodegradation applications. International Journal of Molecular Sciences, 25(21), Article 11621. https://doi.org/10.3390/ijms252111621
56. Nikolova, M. P., & Chavali, M. S. (2020). Metal oxide nanoparticles as biomedical materials. Biomimetics, 5(2), Article 27. https://doi.org/10.3390/biomimetics5020027
57. Parveen, K., Banse, V., & Ledwani, L. (2016). Green synthesis of nanoparticles: Their advantages and disadvantages. In AIP Conference Proceedings (Vol. 1724, No. 1, 020048). AIP Publishing LLC. https://doi.org/10.1063/1.4945168
58. Pasieczna-Patkowska, S., Cichy, M., & Flieger, J. (2025). Application of Fourier transform infrared (FTIR) spectroscopy in characterization of green synthesized nanoparticles. Molecules, 30(3), Article 684. https://doi.org/10.3390/molecules30030684
59. Pokrajac, L., Abbas, A., Chrzanowski, W., Dias, G. M., Eggleton, B. J., Maguire, S., Maine, E., Malloy, T., Nathwani, J., Nazar, L., Sips, A., Sone, J., Van Den Berg, A., Weiss, P. S., & Mitra, S. (2021). Nanotechnology for a sustainable future: Addressing global challenges with the International Network for Sustainable Nanotechnology. ACS Nano, 15(12), 18608–18623. https://doi.org/10.1021/acsnano.1c10919
60. Prasad, T. N. V. K. V., Swethasree, M., Satisha, G. C., Nirmal Kumar, A. R., Sudhakar, P., Ravindra Reddy, B., Saritha, M., Sabitha, N., Bhaskar Reddy, B. V., Rajasekhar, P., Prasanthi, L., Girish, B. P., & Roy Choudhury, S. (2023). Nanoparticulate silica internalization and its effect on the growth and yield of groundnut (Arachis hypogaea L.). Environmental Science & Technology, 57(14), 5881–5890. https://doi.org/10.1021/acs.est.3c00327
61. Raju, D., Paneliya, N., & Mehta, U. J. (2014). Extracellular synthesis of silver nanoparticles using living peanut seedling. Applied Nanoscience, 4(7), 875–879. https://doi.org/10.1007/s13204-013-0269-y
62. Ramachandran, R., Parthasarathy, R., & Dhayalan, S. (2022). Silver nanoparticles synthesized by Euphorbia hirta exhibited antibacterial activity and induced apoptosis through downregulation of PI3Kγ mediated PI3K/Akt/mTOR/p70S6K in human lung adenocarcinoma A549 cells. Environmental Toxicology, 37(12), 2865–2876. https://doi.org/10.1002/tox.23643
63. Rana, A., Yadav, K., & Jagadevan, S. (2020). A comprehensive review on green synthesis of nature-inspired metal nanoparticles: Mechanism, application and toxicity. Journal of Cleaner Production, 272, Article 122880. https://doi.org/10.1016/j.jclepro.2020.122880
64. Rana, S., & Kalaichelvan, P. T. (2013). Ecotoxicity of nanoparticles. International Scholarly Research Notices, 2013, Article 574648. https://doi.org/10.1155/2013/574648
65. Romero, G., & Moya, S. E. (2012). Synthesis of organic nanoparticles. In Frontiers of Nanoscience (Vol. 4, pp. 115–141). Elsevier. https://doi.org/10.1016/B978-0-12-415769-9.00004-2
66. Saha, T., Bin Mobarak, M., Uddin, M. N., Quddus, M. S., Naim, M. R., & Pinky, N. S. (2023). Biogenic synthesis of copper oxide (CuO) nanoparticles exploiting Averrhoa carambola leaf extract and its potential antibacterial activity. Materials Chemistry and Physics, 305, Article 127979. https://doi.org/10.1016/j.matchemphys.2023.127979
67. Sahu, T., Bisht, S. S., Das, K. R., & Kerkar, S. (2013). Nanoceria: Synthesis and biomedical applications. Current Nanoscience, 9(5), 588–593. https://doi.org/10.2174/15734137113099990084
68. Sajid, M. (2022). Nanomaterials: types, properties, recent advances, and toxicity concerns. Current Opinion in Environmental Science & Health, 25, Article 100319. https://doi.org/10.1016/j.coesh.2021.100319
69. Salata, O. V. (2004). Applications of nanoparticles in biology and medicine. Journal of Nanobiotechnology, 2(1), 1–6. https://doi.org/10.1186/1477-3155-2-3
70. Salem, S. S., & Fouda, A. (2021). Green synthesis of metallic nanoparticles and their prospective biotechnological applications: An overview. Biological Trace Element Research, 199(1), 344–370. https://doi.org/10.1007/s12011-020-02138-3
71. Sarkar, N., Sharma, R. S., & Kaushik, M. (2021). Innovative application of facile single pot green synthesized CuO and CuO@APTES nanoparticles in nanopriming of Vigna radiata seeds. Environmental Science and Pollution Research, 28(11), 13221–13228. https://doi.org/10.1007/s11356-020-11493-6
72. Sati, A., Ranade, T. N., Mali, S. N., Yasin, H. K. A., & Pratap, A. (2025). Silver nanoparticles (AgNPs): Comprehensive insights into bio/synthesis, key influencing factors, multifaceted applications, and toxicity—a 2024 update. ACS Omega, 10(8), 7549–7582. https://doi.org/10.1021/acsomega.4c11045
73. Shang, H., Ma, C., Li, C., Cai, Z., Shen, Y., Han, L., Wang, C., Tran, J., Elmer, W. H., White, J. C., & Xing, B. (2023). Aloe vera extract gel-biosynthesized selenium nanoparticles enhance disease resistance in lettuce by modulating the metabolite profile and bacterial endophyte composition. ACS Nano, 17(14), 13672–13684. https://doi.org/10.1021/acsnano.3c02790
74. Shrestha, S., Wang, B., & Dutta, P. (2020). Nanoparticle processing: Understanding and controlling aggregation. Advances in Colloid and Interface Science, 279, Article 102162. https://doi.org/10.1016/j.cis.2020.102162
75. Siddiqi, K. S., Ur Rahman, A., Tajuddin, N., & Husen, A. (2018). Properties of zinc oxide nanoparticles and their activity against microbes. Nanoscale Research Letters, 13(1), Article 141. https://doi.org/10.1186/s11671-018-2532-3
76. Singh, H., Desimone, M. F., Pandya, S., Jasani, S., George, N., Adnan, M., Aldarhami, A., Bazaid, A. S., & Alderhami, S. A. (2023). Revisiting the green synthesis of nanoparticles: Uncovering influences of plant extracts as reducing agents for enhanced synthesis efficiency and its biomedical applications. International Journal of Nanomedicine, 18, 4727–4750. https://doi.org/10.2147/ijn.s419369
77. Singh, P., Pandit, S., Mokkapati, V. R. S. S., Garg, A., Ravikumar, V., & Mijakovic, I. (2018). Gold nanoparticles in diagnostics and therapeutics for human cancer. International Journal of Molecular Sciences, 19(7), Article 1979. https://doi.org/10.3390/ijms19071979
78. Song, J. Y., Jang, H. K., & Kim, B. S. (2009). Biological synthesis of gold nanoparticles using Magnolia kobus and Diospyros kaki leaf extracts. Process Biochemistry, 44(10), 1133–1138. https://doi.org/10.1016/j.procbio.2009.06.005
79. Sreekanth, T. V. M., Nagajyothi, P. C., Muthuraman, P., Enkhtaivan, G., Vattikuti, S. V. P., Tettey, C. O., Kim, D. H., Shim, J., & Yoo, K. (2018). Ultra-sonication-assisted synthesis of silver nanoparticles using Panax ginseng root extract and their anti-cancer and antiviral activities. Journal of Photochemistry and Photobiology B: Biology, 188, 6–11. https://doi.org/10.1016/j.jphotobiol.2018.08.013
80. Sundrarajan, M., & Muthulakshmi, V. (2021). Green synthesis of ionic liquid mediated neodymium oxide nanoparticles by Andrographis paniculata leaves extract for effective biomedical applications. Journal of Environmental Chemical Engineering, 9(1), Article 104716. https://doi.org/10.1016/j.jece.2020.104716
81. Teleanu, D. M., Chircov, C., Grumezescu, A. M., Volceanov, A., & Teleanu, R. I. (2018). Impact of nanoparticles on brain health: An up-to-date overview. Journal of Clinical Medicine, 7(12), Article 490. https://doi.org/10.3390/jcm7120490
82. Testa, C., Zammataro, A., Pappalardo, A., & Trusso Sfrazzetto, G. (2019). Catalysis with carbon nanoparticles. RSC Advances, 9(47), 27659–27664. https://doi.org/10.1039/C9RA05689K
83. Tunkaew, K., Liewhiran, C., & Vaddhanaphuti, C. S. (2024). Functionalized metal oxide nanoparticles: A promising intervention against major health burden of diseases. Life Sciences, 358, Article 123154. https://doi.org/10.1016/j.lfs.2024.123154
84. Usman, M., Farooq, M., Wakeel, A., Nawaz, A., Cheema, S. A., Rehman, H. U., Ashraf, I., & Sanaullah, M. (2020). Nanotechnology in agriculture: Current status, challenges and future opportunities. Science of the Total Environment, 721, Article 137778. https://doi.org/10.1016/j.scitotenv.2020.137778
85. Vinayagam, R., Hebbar, A., Senthil Kumar, P., Rangasamy, G., Varadavenkatesan, T., Murugesan, G., Srivastava, S., Goveas, L. C., Kumar, N. M., & Selvaraj, R. (2023). Green synthesized cobalt oxide nanoparticles with photocatalytic activity towards dye removal. Environmental Research, 216, Article 114766. https://doi.org/10.1016/j.envres.2022.114766
86. Vladár, A. E., & Hodoroaba, V. D. (2020). Characterization of nanoparticles by scanning electron microscopy. In V.-D. Hodoroaba, W. E. S. Unger, & A. G. Shard (Eds.), Characterization of nanoparticles: Measurement processes for nanoparticles (pp. 7–27). Elsevier. https://doi.org/10.1016/B978-0-12-814182-3.00002-X
87. Wu, W., Wu, Z., Yu, T., Jiang, C., & Kim, W. S. (2015). Recent progress on magnetic iron oxide nanoparticles: Synthesis, surface functional strategies and biomedical applications. Science and Technology of Advanced Materials, 16(2), Article 023501. https://doi.org/10.1088/1468-6996/16/2/023501
88. Ying, S., Guan, Z., Ofoegbu, P. C., Clubb, P., Rico, C., He, F., & Hong, J. (2022). Green synthesis of nanoparticles: Current developments and limitations. Environmental Technology & Innovation, 26, Article 102336. https://doi.org/10.1016/j.eti.2022.102336
89. Zulfiqar, Z., Khan, R. R. M., Summer, M., Saeed, Z., Pervaiz, M., Rasheed, S., Shehzad, B., Kabir, F., & Ishaq, S. (2024). Plant-mediated green synthesis of silver nanoparticles: Synthesis, characterization, biological applications, and toxicological considerations: A review. Biocatalysis and Agricultural Biotechnology, 57, Article 103121. https://doi.org/10.1016/j.bcab.2024.103121