logo

SCIENCE CHINA Materials, Volume 62 , Issue 11 : 1727-1739(2019) https://doi.org/10.1007/s40843-019-9471-7

Antibacterial mechanism and activity of cerium oxide nanoparticles

More info
  • ReceivedMay 15, 2019
  • AcceptedJul 1, 2019
  • PublishedAug 12, 2019

Abstract


Funded by

the National Funds for Excellent Young Scientists of China(21522106)

the National Key R&D Program of China(2017YFA0208000)

the 111 Project(B18030)


Acknowledgment

We gratefully acknowledge the support from the National Funds for Excellent Young Scientists of China (21522106), the National Key R&D Program of China (2017YFA0208000), and the 111 Project (B18030) from China.


Interest statement

The authors declare no conflict of interest.


Contributions statement

Du Y and Yan C proposed the overall concept. Zhang M wrote the paper with the guidance from Du Y, Luo F and Zhai X; Zhang M, Zhang C and Zhai X revised the manuscript. All authors contributed to the general discussion.


Author information

Mengzhen Zhang is a PhD student at the School of Chemistry, Nankai University. Her research interest focuses on the rare earth based functional materials.


Xinyun Zhai is a lecturer at the School of Material Science and Engineering, Nankai University. She received her BSc degree and MSc degree from Tianjin University in 2010 and 2013, respectively and PhD degree from The University of Hong Kong in 2017. Her research interests focus on rare-earth based biomedical materials and rare-earth based functional materials.


Yaping Du is a full professor at the School of Material Science and Engineering, Nankai University. He is the director of Tianjin Key Lab for Rare Earth Materials and Applications and Deputy Director of the Centre for Rare Earth and Inorganic Functional Materials. His research interests focus on rare-earth functional materials. He has more than 90 publications in peer-reviewed scientific journals and was a winner of the National Science Fund for Excellent Young Scholars in 2015. He received his BSc degree from Lanzhou University in 2004 and PhD degree from Peking University in 2009.


Chunhua Yan is the President of Lanzhou University and the Director of the State Key Laboratory of Rare Earth Materials Chemistry and Applications at Peking University, and the Center for Rare Earth and Inorganic Functional Materials at Nankai University. He received his BSc, MSc, and PhD degrees from Peking University.


References

[1] Stryjewski ME, Corey GR. Methicillin-resistant staphylococcus aureus: An evolving pathogen. Clin Infect Dis, 2014, 58: S10-S19 CrossRef PubMed Google Scholar

[2] Seil JT, Webster TJ. Antimicrobial applications of nanotechnology: methods and literature. Int J Nanomed, 2012, 7: 2767 CrossRef PubMed Google Scholar

[3] Shrivastava S, Bera T, Roy A, et al. Characterization of enhanced antibacterial effects of novel silver nanoparticles. Nanotechnology, 2007, 18: 225103 CrossRef ADS Google Scholar

[4] Sondi I, Salopek-Sondi B. Silver nanoparticles as antimicrobial agent: A case study on E. coli as a model for Gram-negative bacteria. J Colloid Interface Sci, 2004, 275: 177-182 CrossRef PubMed ADS Google Scholar

[5] Stoimenov PK, Klinger RL, Marchin GL, et al. Metal oxide nanoparticles as bactericidal agents. Langmuir, 2002, 18: 6679-6686 CrossRef Google Scholar

[6] Tran AX, Lester ME, Stead CM, et al. Resistance to the antimicrobial peptide polymyxin requires myristoylation of escherichia coli and salmonella typhimurium lipid A. J Biol Chem, 2005, 280: 28186-28194 CrossRef PubMed Google Scholar

[7] Usman MS, El Zowalaty ME, Shameli K, et al. Synthesis, characterization, and antimicrobial properties of copper nanoparticles. Int J Nanomed, 2013, 8: 4467 CrossRef PubMed Google Scholar

[8] Jones N, Ray B, Ranjit KT, et al. Antibacterial activity of ZnO nanoparticle suspensions on a broad spectrum of microorganisms. FEMS MicroBiol Lett, 2008, 279: 71-76 CrossRef PubMed Google Scholar

[9] Cho M, Chung H, Choi W, et al. Linear correlation between inactivation of E. coli and OH radical concentration in TiO2 photocatalytic disinfection. Water Res, 2004, 38: 1069-1077 CrossRef PubMed Google Scholar

[10] AshaRani PV, Low Kah Mun G, Hande MP, et al. Cytotoxicity and genotoxicity of silver nanoparticles in human cells. ACS Nano, 2008, 3: 279-290 CrossRef PubMed Google Scholar

[11] Tarnuzzer RW, Colon J, Patil S, et al. Vacancy engineered ceria nanostructures for protection from radiation-induced cellular damage. Nano Lett, 2005, 5: 2573-2577 CrossRef PubMed ADS Google Scholar

[12] Tsai YY, Oca-Cossio J, Agering K, et al. Novel synthesis of cerium oxide nanoparticles for free radical scavenging. Nanomedicine, 2007, 2: 325-332 CrossRef PubMed Google Scholar

[13] Park B, Donaldson K, Duffin R, et al. Hazard and risk assessment of a nanoparticulate cerium oxide-based diesel fuel additive—A case study. Inhalation Toxicol, 2008, 20: 547-566 CrossRef Google Scholar

[14] De Marzi L, Monaco A, De Lapuente J, et al. Cytotoxicity and genotoxicity of ceria nanoparticles on different cell lines in vitro. Int J Mol Sci, 2013, 14: 3065-3077 CrossRef PubMed Google Scholar

[15] Ingle AP, Duran N, Rai M. Bioactivity, mechanism of action, and cytotoxicity of copper-based nanoparticles: A review. Appl Microbiol Biotechnol, 2014, 98: 1001-1009 CrossRef PubMed Google Scholar

[16] Chen BH, Suresh Babu K, Anandkumar M, et al. Cytotoxicity and antibacterial activity of gold-supported cerium oxide nanoparticles. Int J Nanomed, 2014, 9: 5515 CrossRef PubMed Google Scholar

[17] Sun C, Li H, Chen L. Nanostructured ceria-based materials: Synthesis, properties, and applications. Energy Environ Sci, 2012, 5: 8475 CrossRef Google Scholar

[18] Wang X, Jiang Z, Zheng B, et al. Synthesis and shape-dependent catalytic properties of CeO2 nanocubes and truncated octahedra. CrystEngComm, 2012, 14: 7579-7582 CrossRef Google Scholar

[19] Wang Y, Liu R, LüG M, et al. Ceria nanostructures and their catalytic applications. J Chin Rare Earth Soc, 2014, 32: 257 CrossRef Google Scholar

[20] Xing S, Yu S, Deng Y, et al. Effect of cerium on abrasive wear behaviour of hardfacing alloy. J Rare Earths, 2012, 30: 69-73 CrossRef Google Scholar

[21] Feng X, Sayle DC, Wang ZL, et al. Converting ceria polyhedral nanoparticles into single-crystal nanospheres. Science, 2006, 312: 1504-1508 CrossRef PubMed ADS Google Scholar

[22] Yahiro H. High temperature fuel cell with ceria-yttria solid electrolyte. J Electrochem Soc, 1988, 135: 2077 CrossRef Google Scholar

[23] Atkinson A, Barnett S, Gorte RJ, et al. Advanced Anodes for High-Temperature Fuel Cells. Materials for Sustainable Energy: A Collection of Peer-Reviewed Research and Review Articles from Nature Publishing Group. Singapore: World Scientific, 2010, 213–223. Google Scholar

[24] Lv GM, Wang YJ, Liu R, et al. The application of nanoceria in the bio-antioxidation. Sci Sin Chim, 2013, 43: 1309-1321 CrossRef Google Scholar

[25] Li R. Synthesis and UV-shielding properties of ZnO- and CaO-doped CeO2 via soft solution chemical process. Solid State Ion, 2002, 151: 235-241 CrossRef Google Scholar

[26] Hirst SM, Karakoti AS, Tyler RD, et al. Anti-inflammatory properties of cerium oxide nanoparticles. Small, 2009, 5: 2848-2856 CrossRef PubMed Google Scholar

[27] Trovarelli A, Fornasiero P. Catalysis by Ceria and Related Materials. Singapore: World Scientific, 2013. Google Scholar

[28] Blank JH, Beckers J, Collignon PF, et al. Redox kinetics of ceria-based mixed oxides in selective hydrogen combustion. ChemPhysChem, 2007, 8: 2490-2497 CrossRef PubMed Google Scholar

[29] Chen HT, Choi YM, Liu M, et al. A theoretical study of surface reduction mechanisms of CeO2 (111) and (110) by H2. ChemPhysChem, 2007, 8: 849-855 CrossRef PubMed Google Scholar

[30] Mo L, Zheng X, Yeh CT. A novel CeO2/ZnO catalyst for hydrogen production from the partial oxidation of methanol. ChemPhysChem, 2005, 6: 1470-1472 CrossRef PubMed Google Scholar

[31] Jasinski P, Suzuki T, Anderson HU. Nanocrystalline undoped ceria oxygen sensor. Senor Actuat B-Chem, 2003, 95: 73-77 CrossRef Google Scholar

[32] Eguchi K, Setoguchi T, Inoue T, et al. Electrical properties of ceria-based oxides and their application to solid oxide fuel cells. Solid State Ion, 1992, 52: 165-172 CrossRef Google Scholar

[33] Keating PRL, Scanlon DO, Watson GW. Intrinsic ferromagnetism in CeO2: Dispelling the myth of vacancy site localization mediated superexchange. J Phys-Condens Matter, 2009, 21: 405502 CrossRef PubMed ADS Google Scholar

[34] Song YQ, Zhang HW, Yang QH, et al. Electronic structure and magnetic properties of Co-doped CeO2: based on first principle calculation. J Phys-Condens Matter, 2009, 21: 125504 CrossRef PubMed ADS Google Scholar

[35] Shoko E, Smith MF, McKenzie RH. Charge distribution near bulk oxygen vacancies in cerium oxides. J Phys-Condens Matter, 2010, 22: 223201 CrossRef PubMed ADS arXiv Google Scholar

[36] Skorodumova NV, Simak SI, Lundqvist BI, et al. Quantum origin of the oxygen storage capability of ceria. Phys Rev Lett, 2002, 89: 166601 CrossRef PubMed ADS Google Scholar

[37] Deshpande S, Patil S, Kuchibhatla SV, et al. Size dependency variation in lattice parameter and valency states in nanocrystalline cerium oxide. Appl Phys Lett, 2005, 87: 133113 CrossRef ADS Google Scholar

[38] Krishnamoorthy K, Veerapandian M, Zhang LH, et al. Surface chemistry of cerium oxide nanocubes: Toxicity against pathogenic bacteria and their mechanistic study. J Ind Eng Chem, 2014, 20: 3513-3517 CrossRef Google Scholar

[39] Korsvik C, Patil S, Seal S, et al. Superoxide dismutase mimetic properties exhibited by vacancy engineered ceria nanoparticles. Chem Commun, 2007, 303: 1056-1058 CrossRef PubMed Google Scholar

[40] Pirmohamed T, Dowding JM, Singh S, et al. Nanoceria exhibit redox state-dependent catalase mimetic activity. Chem Commun, 2010, 46: 2736-2738 CrossRef PubMed Google Scholar

[41] Asati A, Santra S, Kaittanis C, et al. Oxidase-like activity of polymer-coated cerium oxide nanoparticles. Angew Chem Int Ed, 2009, 48: 2308-2312 CrossRef PubMed Google Scholar

[42] Huang Y, Ren J, Qu X. Nanozymes: Classification, catalytic mechanisms, activity regulation, and applications. Chem Rev, 2019, 119: 4357-4412 CrossRef PubMed Google Scholar

[43] Gupta A, Das S, Neal CJ, et al. Controlling the surface chemistry of cerium oxide nanoparticles for biological applications. J Mater Chem B, 2016, 4: 3195-3202 CrossRef Google Scholar

[44] Schubert D, Dargusch R, Raitano J, et al. Cerium and yttrium oxide nanoparticles are neuroprotective. Biochem BioPhys Res Commun, 2006, 342: 86-91 CrossRef PubMed Google Scholar

[45] Kirchner C, Liedl T, Kudera S, et al. Cytotoxicity of colloidal CdSe and CdSe/ZnS nanoparticles. Nano Lett, 2005, 5: 331-338 CrossRef PubMed ADS Google Scholar

[46] Franklin NM, Rogers NJ, Apte SC, et al. Comparative toxicity of nanoparticulate ZnO, bulk ZnO, and ZnCl2 to a freshwater microalga (Pseudokirchneriella subcapitata): The importance of particle solubility. Environ Sci Technol, 2007, 41: 8484-8490 CrossRef ADS Google Scholar

[47] Hoecke KV, Quik JTK, Mankiewicz-Boczek J, et al. Fate and effects of CeO2 nanoparticles in aquatic ecotoxicity tests. Environ Sci Technol, 2009, 43: 4537-4546 CrossRef ADS Google Scholar

[48] Dickson JS, Koohmaraie M. Cell surface charge characteristics and their relationship to bacterial attachment to meat surfaces. Appl Environ Microbiol, 1989, 55: 832–836. Google Scholar

[49] Thill A, Zeyons O, Spalla O, et al. Cytotoxicity of CeO2 nanoparticles for escherichia coli. physico-chemical insight of the cytotoxicity mechanism. Environ Sci Technol, 2006, 40: 6151-6156 CrossRef ADS Google Scholar

[50] Zeyons O, Thill A, Chauvat F, et al. Direct and indirect CeO2 nanoparticles toxicity for escherichia coli and synechocystis. Nanotoxicology, 2009, 3: 284-295 CrossRef Google Scholar

[51] Pelletier DA, Suresh AK, Holton GA, et al. Effects of engineered cerium oxide nanoparticles on bacterial growth and viability. Appl Environ MicroBiol, 2010, 76: 7981-7989 CrossRef PubMed Google Scholar

[52] He X, Kuang Y, Li Y, et al. Changing exposure media can reverse the cytotoxicity of ceria nanoparticles for escherichia coli. Nanotoxicology, 2012, 6: 233-240 CrossRef PubMed Google Scholar

[53] Sobek JM, Talburt DE. Effects of the rare earth cerium on Escherichia coli. J Bacteriol, 1968, 95: 47-51 Google Scholar

[54] Li Y, Zhang W, Niu J, et al. Mechanism of photogenerated reactive oxygen species and correlation with the antibacterial properties of engineered metal-oxide nanoparticles. ACS Nano, 2012, 6: 5164-5173 CrossRef PubMed Google Scholar

[55] Aruguete DM, Kim B, Hochella MF, et al. Antimicrobial nanotechnology: Its potential for the effective management of microbial drug resistance and implications for research needs in microbial nanotoxicology. Environ Sci-Processes Impacts, 2013, 15: 93-102 CrossRef Google Scholar

[56] Alpaslan E, Geilich BM, Yazici H, et al. pH-controlled cerium oxide nanoparticle inhibition of both Gram-positive and Gram-negative bacteria growth. Sci Rep, 2017, 7: 45859 CrossRef PubMed ADS Google Scholar

[57] Arumugam A, Karthikeyan C, Haja Hameed AS, et al. Synthesis of cerium oxide nanoparticles using Gloriosa superba L. leaf extract and their structural, optical and antibacterial properties. Mater Sci Eng-C, 2015, 49: 408-415 CrossRef PubMed Google Scholar

[58] Tong GX, Du FF, Liang Y, et al. Polymorphous ZnO complex architectures: Selective synthesis, mechanism, surface area and Zn-polar plane-codetermining antibacterial activity. J Mater Chem B, 2013, 1: 454-463 CrossRef Google Scholar

[59] Akhavan O, Ghaderi E. Toxicity of graphene and graphene oxide nanowalls against bacteria. ACS Nano, 2010, 4: 5731-5736 CrossRef PubMed Google Scholar

[60] Charbgoo F, Ahmad MB, Darroudi M. Cerium oxide nanoparticles: Green synthesis and biological applications. Int J Nanomed, 2017, Volume 12: 1401-1413 CrossRef PubMed Google Scholar

[61] Farias IAP, Dos Santos CCL, Sampaio FC. Antimicrobial activity of cerium oxide nanoparticles on opportunistic microorganisms: A systematic review. Biomed Res Int, 2018, 2018(3): 1-14 CrossRef PubMed Google Scholar

[62] Roduner E. Size matters: Why nanomaterials are different. Chem Soc Rev, 2006, 35: 583-592 CrossRef PubMed Google Scholar

[63] Farokhzad OC, Cheng J, Teply BA, et al. Targeted nanoparticle-aptamer bioconjugates for cancer chemotherapy in vivo. Proc Natl Acad Sci USA, 2006, 103: 6315-6320 CrossRef PubMed ADS Google Scholar

[64] Kuang Y, He X, Zhang Z, et al. Comparison study on the antibacterial activity of nano- or bulk-cerium oxide. J Nanosci Nanotech, 2011, 11: 4103-4108 CrossRef Google Scholar

[65] Gottenbos B, Grijpma DW, van der Mei HC, et al. Antimicrobial effects of positively charged surfaces on adhering Gram-positive and Gram-negative bacteria. J Antimicrob Chemother, 2001, 48: 7-13 CrossRef PubMed Google Scholar

[66] Zhu Y, Ran T, Li Y, et al. Dependence of the cytotoxicity of multi-walled carbon nanotubes on the culture medium. Nanotechnology, 2006, 17: 4668-4674 CrossRef PubMed ADS Google Scholar

[67] Limbach LK, Li Y, Grass RN, et al. Oxide nanoparticle uptake in human lung fibroblasts: Effects of particle size, agglomeration, and diffusion at low concentrations. Environ Sci Technol, 2005, 39: 9370-9376 CrossRef ADS Google Scholar

[68] Mathew TV, Kuriakose S. Studies on the antimicrobial properties of colloidal silver nanoparticles stabilized by bovine serum albumin. Colloids Surfs B-Biointerfaces, 2013, 101: 14-18 CrossRef PubMed Google Scholar

[69] Babenko L, Zholobak N, Shcherbakov A, et al. Antibacterial activity of cerium colloids against opportunistic microorganisms in vitro. Mikrobiolohichnyĭ zhurnal, 2012, 74: 54-62 Google Scholar

[70] Surendra TV, Roopan SM. Photocatalytic and antibacterial properties of phytosynthesized CeO2 NPs using Moringa oleifera peel extract. J PhotoChem PhotoBiol B-Biol, 2016, 161: 122-128 CrossRef PubMed Google Scholar

[71] Cuahtecontzi-Delint R, Mendez-Rojas MA, Bandala ER, et al. Enhanced antibacterial activity of CeO2 nanoparticles by surfactants. Int J Chem Reactor Eng, 2013, 11: 781}-785 CrossRef Google Scholar

[72] Maqbool Q, Nazar M, Naz S, et al. Antimicrobial potential of green synthesized CeO2 nanoparticles from Olea europaea leaf extract. Int J Nanomed, 2016, Volume 11: 5015-5025 CrossRef PubMed Google Scholar

[73] Patil SN, Paradeshi JS, Chaudhari PB, et al. Bio-therapeutic potential and cytotoxicity assessment of pectin-mediated synthesized nanostructured cerium oxide. Appl Biochem Biotechnol, 2016, 180: 638-654 CrossRef PubMed Google Scholar

[74] Gopinath K, Karthika V, Sundaravadivelan C, et al. Mycogenesis of cerium oxide nanoparticles using Aspergillus niger culture filtrate and their applications for antibacterial and larvicidal activities. J Nanostruct Chem, 2015, 5: 295-303 CrossRef Google Scholar

[75] Reddy Yadav LS, Manjunath K, Archana B, et al. Fruit juice extract mediated synthesis of CeO2 nanoparticles for antibacterial and photocatalytic activities. Eur Phys J Plus, 2016, 131: 154 CrossRef ADS Google Scholar

[76] Malleshappa J, Nagabhushana H, Sharma SC, et al. Leucas aspera mediated multifunctional CeO2 nanoparticles: Structural, photoluminescent, photocatalytic and antibacterial properties. SpectroChim Acta Part A-Mol Biomol Spectr, 2015, 149: 452-462 CrossRef PubMed Google Scholar

[77] Ravishankar TN, Ramakrishnappa T, Nagaraju G, et al. Synthesis and characterization of CeO2 nanoparticles via solution combustion method for photocatalytic and antibacterial activity studies. ChemistryOpen, 2015, 4: 146-154 CrossRef PubMed Google Scholar

[78] Wang Q, Perez JM, Webster TJ. Inhibited growth of pseudomonas aeruginosa by dextran- and polyacrylic acid-coated ceria nanoparticles. Int J Nanomed, 2013, 8: 3395 CrossRef PubMed Google Scholar

[79] Huang X, Li LD, Lyu GM, et al. Chitosan-coated cerium oxide nanocubes accelerate cutaneous wound healing by curtailing persistent inflammation. Inorg Chem Front, 2018, 5: 386-393 CrossRef Google Scholar

  • Figure 1

    Schematic of the standard picture of charge redistribution following the formation of an oxygen vacancy in CeO2. The tetrahedron of Ce atoms (black circles) with an O atom at its center (grey (orange in color version) circle) is shown along with the charges on these atoms in the simple ionic picture description of CeO2. The process of reduction shown by the arrow leads to a neutral O vacancy at the center of the tetrahedron (empty circle) while two of the Ce ions have been reduced to the III oxidation state. Reproduced with the permission from Ref. [35]. Copyright 2010, Institute of Physics Science.

  • Figure 2

    The process of oxygen-vacancy formation in ceria. An oxygen atom moves away from its lattice position leaving behind two electrons, which localize on two cerium atoms, turning Ce(IV) into Ce(III). Reproduced with the permission from Ref. [36]. Copyright 2002, American Physical Society.

  • Figure 3

    XPS of CeO2 nanocubes. Reproduced with the permission from Ref. [38]. Copyright 2014, Elsevier.

  • Figure 4

    Isotherm of adsorption of CeO2 NPs on E. coli bacteria. Insets show TEM observations of E. coli ultra microtomic thin sections before and after contact with 12 mg m−2 of adsorbed ceria. The scale bar is 0.1 μm. A zoom shows the multilayer of NPs at the cell outer membrane. Reproduced with the permission from Ref. [49]. Copyright 2006, American Chemical Society.

  • Figure 5

    Representative TEM images showing the interaction of E. coli and the B sample of cerium oxide NPs at different magnifications. The image shows the results of incubating NPs with logarithmic-phase growing bacteria for 30 min at 37°C with shaking, followed by placing a droplet on the TEM grid for 7 min, rinsing in water to remove unbound bacteria and particles, and imaging. Particles apparently stick to the bacterial surfaces but are not internalized by E. coli. Reproduced with the permission from Ref. [51]. Copyright 2010, the American Society for Microbiology (ASM).

  • Figure 6

    ROS generation of Gram-negative bacteria P. aeruginosa (a) and Gram-positive bacteria S. epidermidis (b) per colony after treatment with 500 μg mL−1 nanoceria at pH 9 for 6 h. Values represent the mean +/−SEM, N = 3 and *p< 0.05 compared with the untreated control. Reproduced with the permission from Ref. [56]. Copyright 2017, Nature Publishing Group.

  • Figure 7

    Diagrammatic representation of toxicity of CeO2 NPs against bacterial pathogens.

  • Figure 8

    Zeta potential of 0.1 mol L−1 dextran coated cerium oxide NPs dispersed in PBS at pH 6 and pH 9. Reproduced with the permission from Ref. [56]. Copyright 2017, Nature Publishing Group.

  • Figure 9

    Zeta potential and dynamic light scattering measurements of the B sample of CeO2 NPs. The zeta potential of the B sample of CeO2 NPs in water and M9, B. subtilis minimal, and HBA media under different pH conditions are shown. Similar results were obtained with the other NP samples. Reproduced with the permission from Ref. [51]. Copyright 2010, ASM.

  • Table 1   Recent studies of antibacterial activities of CeO NPs against and

    Synthesis method

    Salt precursor

    Green raw materials

    Particle size

    Bacteria strains

    Ref.

    Electron microscopy (nm)

    FDS* and others

    (nm)

    E. coli

    S. aureus

     

    Hydrotermal

    microwave

    Ce(NO3)3

    7D

    +

    +

    [69]

    (NH4)2Ce(NO3)3

    Moringa oleifera peel extract

    45T

    +

    +

    [70]

    Precipitation

    Ce(NO3)3

    6.6–45T

    [15

    +

    -

    [51,52]

    100

    +

    -

    [71]

    7&25T

    +

    -

    [63]

    Olea europaea leaf extract

    24S,T

    +

    +

    [72]

    Pectin fruit peel, Citrus maxima

    5–40S

    23.71*

    +

    -

    [73]

    CeCl3·7H2O

    Gloriosa superba L. leaf extract

    5T

    +

    +

    [57]

    Aspergillus niger

    10T

    14.95*

    +

    -

    [74]

    Acalypha indica leaf extract

    8–54T

    36.2*

    +

    +

    [70]

    Ce4+(NO3)4

    7X

    +

    -

    [49]

    Sonochemical

    (ultrasonication)

    Ce(NO3)3·6H2O

    20T

    25*

    +

    -

    [38]

    Combustion

    Ce(NO3)3

    Watermelon juice

    36*

    +

    +

    [75]

    Ce(NO3)3

    Leaf extractLeucas aspera

    4.3–4.6*

    +

    +

    [76]

    (NH4)2Ce(NO3)3

    42T

    35*

    -

    +

    [77]

    TEM; S) scanning electron microscopy; *) Debye-Scherrer formula; X) X-ray scattering at a low angle; D) dynamic light scattering; source: original source.

qqqq

Contact and support