由於含硒的基材具有諸多的生化和生理特性, 例如:抗癌、抗氧化、提升人體免疫力、抗有毒重金屬，因此廣泛的應用於各個領域。而硒奈米基材更能充分的展示其出色的性能, 因此本論文主要研究含硒奈米酶的合成、抗氧化和抗菌性質。多種不同的表面塗層材料被用於合成穩定的奈米顆粒(SeNPs)，其中包括聚(N-乙烯基吡咯烷酮)、有殺菌功能的羧甲基殼聚醣 (SeCMCS)、聚多巴胺 (Se@PDA)和單寧酸(Se@TA)。其中Se@TA顯示出最好的1,1-diphenyl-2-picrylhydrazyl (DPPH)自由基的去除效果, 主要是單寧酸發揮抗氧化作用, 在40 μg/mL的濃度下可將95%的DPPH自由基活性清除, 此外, Se@TA還對H2O2產生的羥基自由基（•OH）表現出最佳的清除效果, 在一小時內可清除超過90%的羥基自由基。研究也發現所製備的含硒奈米顆粒具有奈米酶的功能，受pH值的影響能產生與清除羥基自由基, 由於羥基自由基（•OH）是很強效的活性氧(ROS), 並且具有很強的抗菌活性，因此使用革蘭氏陰性（大腸桿菌）和革蘭氏陽性（金黃色葡萄球菌）測試了奈米酶的抗菌活性, 結果顯示所有奈米酶都顯示出良好的抗金黃色葡萄球菌活性。接觸50 μg/mL 和 100 μg/mL的SeNPs、SeCMCS、Se@PDA 和 Se@TA兩小時後, 幾乎 可100% 將金黃色葡萄球菌殺死。

Selenium (Se)-based materials have broad applications in many fields including anti-cancer, anti-oxidation, boosting human immunity, antagonizing toxic heavy metals, and synthesis due to their biochemical and physiological properties. When being engineered to nano-scale, selenium-based nanomaterials have strongly demonstrated their outstanding properties. This work investigated the synthesis, antioxidant and antimicrobials of selenium-based nanozymes in which hydroxyl radicals could be either generated or scavenged due to the pH value of reaction medium. Hydroxyl radical (•OH) is one of the well-known and powerful reactive oxygen species (ROS) which has a strong antibacterial activity. In this study, several selenium-based nanozymes were synthesised and characterisation including poly(N-vinylpyrrolidone)-stabilised selenium nanoparticles (SeNPs), carboxymethyl chitosan-coated selenium-based nanozymes (SeCMCS), polydopamine-coated selenium nanoyzmes (Se@PDA), and tannic acid-coated nanoyzymes (Se@TA). Dynamic light scattering (DLS), Fourier transform infrared (FTIR) spectroscopy, and field emission scanning electron microscope (FE-SEM) were employed to characterize these selenium nanoparticles. The antioxidant activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals shows that bioactive compounds coated on SeNPs play the major antioxidant effect over bare SeNPs. Among selenium-based nanozymes, Se@TA has shown the best effect with 95% of scavenging activity that was reached at the concentration of 40 μg/mL. Among selenium-based nanozymes, Se@TA has shown the best antioxidant effect that 95% of scavenging activity was reached at the concentration of 40 μg/mL. Furthermore, Se@TA has also demonstrated the best scavenging effect on hydroxyl radicals generated by H2O2 that more than 90% hydroxyl radicals were removed in 1 hour. Antibacterial activity of each nanozyme were tested with both gram- negative (E. coli) and gram-positive (S. aureus) bacteria in which all of the namozymes have shown much better activity against S. aureus. In addition, nearly 100% of S. aureus was killed after 2 hours of contact with 50 μg/mL and 100 μg/mL for all SeNPs, SeCMCS, Se@PDA, and Se@TA.

[1] J. K. Wrobel, R. Power, and M. Toborek, "Biological activity of selenium: Revisited," IUBMB life, vol. 68, no. 2, pp. 97-105, 2016.
[2] J. A. Izbicki and T. Harms, Selenium concentrations in leaf material from Astragalus oxyphysus (diablo locoweed) and Atriplex lentiformis (quail bush) in the interior coast ranges and the western San Joaquin Valley, California (no. 4066). US Department of the Interior, Geological Survey, 1986.
[3] M. Bodnar, M. Szczyglowska, P. Konieczka, and J. Namiesnik, "Methods of selenium supplementation: bioavailability and determination of selenium compounds," Critical reviews in food science and nutrition, vol. 56, no. 1, pp. 36-55, 2016.
[4] M. Vinceti, T. Filippini, and L. A. Wise, "Environmental selenium and human health: an update," Current environmental health reports, vol. 5, no. 4, pp. 464-485, 2018.
[5] M. P. Rayman, "The importance of selenium to human health," The lancet, vol. 356, no. 9225, pp. 233-241, 2000.
[6] M. Roman, P. Jitaru, and C. Barbante, "Selenium biochemistry and its role for human health," Metallomics, vol. 6, no. 1, pp. 25-54, 2014.
[7] B. Hosnedlova et al., "Nano-selenium and its nanomedicine applications: a critical review," International journal of nanomedicine, vol. 13, p. 2107, 2018.
[8] T. Huang, J. A. Holden, E. C. Reynolds, D. E. Heath, N. M. O’Brien-Simpson, and A. J. O’Connor, "Multifunctional antimicrobial polypeptide-selenium nanoparticles combat drug-resistant bacteria," ACS Applied Materials & Interfaces, vol. 12, no. 50, pp. 55696-55709, 2020.
[9] G. Zhao, X. Wu, P. Chen, L. Zhang, C. S. Yang, and J. Zhang, "Selenium nanoparticles are more efficient than sodium selenite in producing reactive oxygen species and hyper-accumulation of selenium nanoparticles in cancer cells generates potent therapeutic effects," Free Radical Biology and Medicine, vol. 126, pp. 55-66, 2018.
[10] X. Song, Y. Chen, G. Zhao, H. Sun, H. Che, and X. Leng, "Effect of molecular weight of chitosan and its oligosaccharides on antitumor activities of chitosan-selenium nanoparticles," Carbohydrate polymers, vol. 231, p. 115689, 2020.
[11] X. Fu et al., "RGD peptide-conjugated selenium nanoparticles: antiangiogenesis by suppressing VEGF-VEGFR2-ERK/AKT pathway," Nanomedicine: Nanotechnology, Biology and Medicine, vol. 12, no. 6, pp. 1627-1639, 2016.
[12] J. Zhang et al., "Development, physicochemical characterization and cytotoxicity of selenium nanoparticles stabilized by beta-lactoglobulin," International journal of biological macromolecules, vol. 107, pp. 1406-1413, 2018.
[13] N. Filipović et al., "Comparative study of the antimicrobial activity of selenium nanoparticles with different surface chemistry and structure," Frontiers in bioengineering and biotechnology, vol. 8, p. 624621, 2021.
[14] J. Zou et al., "Hyaluronic acid-modified selenium nanoparticles for enhancing the therapeutic efficacy of paclitaxel in lung cancer therapy," Artificial cells, nanomedicine, and biotechnology, vol. 47, no. 1, pp. 3456-3464, 2019.
[15] S. Kara, A roadmap of biomedical engineers and milestones. BoD–Books on Demand, 2012.
[16] G. M. Raghavendra, K. Varaprasad, and T. Jayaramudu, "Biomaterials: design, development and biomedical applications," in Nanotechnology applications for tissue engineering: Elsevier, 2015, pp. 21-44.
[17] M. Zandieh and J. Liu, "Surface Science of Nanozymes and Defining a Nanozyme Unit," Langmuir, vol. 38, no. 12, pp. 3617-3622, 2022.
[18] M. Liang et al., "Fe3O4 magnetic nanoparticle peroxidase mimetic-based colorimetric assay for the rapid detection of organophosphorus pesticide and nerve agent," Analytical chemistry, vol. 85, no. 1, pp. 308-312, 2013.
[19] Y. Huang, C. Liu, F. Pu, Z. Liu, J. Ren, and X. Qu, "A GO–Se nanocomposite as an antioxidant nanozyme for cytoprotection," Chemical Communications, vol. 53, no. 21, pp. 3082-3085, 2017.
[20] F. Pogacean et al., "Graphene based nanomaterials as chemical sensors for hydrogen peroxide–A comparison study of their intrinsic peroxidase catalytic behavior," Sensors and actuators B: Chemical, vol. 213, pp. 474-483, 2015.
[21] Y. Li et al., "Acquired superoxide‐scavenging ability of ceria nanoparticles," Angewandte Chemie, vol. 127, no. 6, pp. 1852-1855, 2015.
[22] W. Li, Z. Liu, C. Liu, Y. Guan, J. Ren, and X. Qu, "Manganese dioxide nanozymes as responsive cytoprotective shells for individual living cell encapsulation," Angewandte Chemie International Edition, vol. 56, no. 44, pp. 13661-13665, 2017.
[23] Y. Zhang et al., "Nanozyme decorated metal–organic frameworks for enhanced photodynamic therapy," ACS nano, vol. 12, no. 1, pp. 651-661, 2018.
[24] C. Ge et al., "Facet energy versus enzyme-like activities: the unexpected protection of palladium nanocrystals against oxidative damage," Acs Nano, vol. 10, no. 11, pp. 10436-10445, 2016.
[25] Y. Hu et al., "Surface-enhanced Raman scattering active gold nanoparticles with enzyme-mimicking activities for measuring glucose and lactate in living tissues," ACS nano, vol. 11, no. 6, pp. 5558-5566, 2017.
[26] Z. Chen, Z. Wang, J. Ren, and X. Qu, "Enzyme mimicry for combating bacteria and biofilms," Accounts of Chemical Research, vol. 51, no. 3, pp. 789-799, 2018.
[27] Y. Gong et al., "Selenium-core nanozymes dynamically regulates Aβ & neuroinflammation circulation: augmenting repair of nervous damage," Chemical Engineering Journal, vol. 418, p. 129345, 2021.
[28] Y. Huang, Z. Liu, C. Liu, Y. Zhang, J. Ren, and X. Qu, "Selenium‐Based Nanozyme as Biomimetic Antioxidant Machinery," Chemistry–A European Journal, vol. 24, no. 40, pp. 10224-10230, 2018.
[29] W. Chen, Y. Li, S. Yang, L. Yue, Q. Jiang, and W. Xia, "Synthesis and antioxidant properties of chitosan and carboxymethyl chitosan-stabilized selenium nanoparticles," Carbohydrate polymers, vol. 132, pp. 574-581, 2015.
[30] B. Seelig and J. W. Szostak, "Selection and evolution of enzymes from a partially randomized non-catalytic scaffold," Nature, vol. 448, no. 7155, pp. 828-831, 2007.
[31] H. J. Forman and H. Zhang, "Targeting oxidative stress in disease: Promise and limitations of antioxidant therapy," Nature Reviews Drug Discovery, vol. 20, no. 9, pp. 689-709, 2021.
[32] E. A. Veal, A. M. Day, and B. A. Morgan, "Hydrogen peroxide sensing and signaling," Molecular cell, vol. 26, no. 1, pp. 1-14, 2007.
[33] R. Zhang, X. Yan, and K. Fan, "Nanozymes inspired by natural enzymes," Accounts of Materials Research, vol. 2, no. 7, pp. 534-547, 2021.
[34] D. Jiang, D. Ni, Z. T. Rosenkrans, P. Huang, X. Yan, and W. Cai, "Nanozyme: new horizons for responsive biomedical applications," Chemical Society Reviews, vol. 48, no. 14, pp. 3683-3704, 2019.
[35] S. Thangudu and C.-H. Su, "Peroxidase mimetic nanozymes in cancer phototherapy: progress and perspectives," Biomolecules, vol. 11, no. 7, p. 1015, 2021.
[36] Z. Tian, J. Li, Z. Zhang, W. Gao, X. Zhou, and Y. Qu, "Highly sensitive and robust peroxidase-like activity of porous nanorods of ceria and their application for breast cancer detection," (in eng), Biomaterials, vol. 59, pp. 116-24, Aug 2015.
[37] S. K. Maji, A. K. Mandal, K. T. Nguyen, P. Borah, and Y. Zhao, "Cancer cell detection and therapeutics using peroxidase-active nanohybrid of gold nanoparticle-loaded mesoporous silica-coated graphene," ACS applied materials & interfaces, vol. 7, no. 18, pp. 9807-9816, 2015.
[38] X. Yan et al., "Oxidase-mimicking activity of ultrathin MnO 2 nanosheets in colorimetric assay of acetylcholinesterase activity," Nanoscale, vol. 9, no. 6, pp. 2317-2323, 2017.
[39] L. Benmoyal-Segal et al., "Acetylcholinesterase/paraoxonase interactions increase the risk of insecticide‐induced Parkinson's disease," The FASEB journal, vol. 19, no. 3, pp. 1-17, 2005.
[40] Z. Wang et al., "Biomimetic RNA‐silencing nanocomplexes: Overcoming multidrug resistance in cancer cells," Angewandte Chemie International Edition, vol. 53, no. 7, pp. 1997-2001, 2014.
[41] H. Wang et al., "Unraveling the enzymatic activity of oxygenated carbon nanotubes and their application in the treatment of bacterial infections," Nano Letters, vol. 18, no. 6, pp. 3344-3351, 2018.
[42] A. M. Klibanov and E. D. Morris, "Horseradish peroxidase for the removal of carcinogenic aromatic amines from water," Enzyme and Microbial Technology, vol. 3, no. 2, pp. 119-122, 1981.
[43] Y. Huang, J. Ren, and X. Qu, "Nanozymes: classification, catalytic mechanisms, activity regulation, and applications," Chemical reviews, vol. 119, no. 6, pp. 4357-4412, 2019.
[44] R. J. Reiter et al., "A review of the evidence supporting melatonin's role as an antioxidant," Journal of pineal research, vol. 18, no. 1, pp. 1-11, 1995.
[45] M. S. Paul, U. K. Aravind, G. Pramod, and C. Aravindakumar, "Oxidative degradation of fensulfothion by hydroxyl radical in aqueous medium," Chemosphere, vol. 91, no. 3, pp. 295-301, 2013.
[46] F. Rineau et al., "The ectomycorrhizal fungus Paxillus involutus converts organic matter in plant litter using a trimmed brown‐rot mechanism involving Fenton chemistry," Environmental Microbiology, vol. 14, no. 6, pp. 1477-1487, 2012.
[47] J. S. Levine, "5.5 - Biomass Burning: The Cycling of Gases and Particulates from the Biosphere to the Atmosphere," in Treatise on Geochemistry (Second Edition), H. D. Holland and K. K. Turekian, Eds. Oxford: Elsevier, 2014, pp. 139-150.
[48] G. McDonnell and A. D. Russell, "Antiseptics and disinfectants: activity, action, and resistance," Clinical microbiology reviews, vol. 12, no. 1, pp. 147-179, 1999.
[49] K. Viacava, E. Ammann, D. Bravo, and M. Lenz, "Low-temperature reactive aerosol processing for large-scale synthesis of selenium nanoparticles," Industrial & Engineering Chemistry Research, vol. 59, no. 36, pp. 16088-16094, 2020.
[50] S. A. Wadhwani et al., "Green synthesis of selenium nanoparticles using Acinetobacter sp. SW30: Optimization, characterization and its anticancer activity in breast cancer cells," International journal of nanomedicine, vol. 12, p. 6841, 2017.
[51] G. Zhang et al., "Systematic study on the reduction efficiency of ascorbic acid and thiourea on selenate and selenite at high and trace concentrations," Environmental Science and Pollution Research, vol. 26, no. 10, pp. 10159-10173, 2019.
[52] Y. Zhuang et al., "Mitochondrion-targeted selenium nanoparticles enhance reactive oxygen species-mediated cell death," Nanoscale, vol. 12, no. 3, pp. 1389-1396, 2020.
[53] M. Vahdati and T. Tohidi Moghadam, "Synthesis and characterization of selenium nanoparticles-lysozyme nanohybrid system with synergistic antibacterial properties," Scientific reports, vol. 10, no. 1, pp. 1-10, 2020.
[54] A. Modrzejewska-Sikorska et al., "Lignosulfonate-stabilized selenium nanoparticles and their deposition on spherical silica," International journal of biological macromolecules, vol. 103, pp. 403-408, 2017.
[55] A. Khurana, S. Tekula, M. A. Saifi, P. Venkatesh, and C. Godugu, "Therapeutic applications of selenium nanoparticles," Biomedicine & Pharmacotherapy, vol. 111, pp. 802-812, 2019/03/01/ 2019.
[56] V. Mourya, N. N. Inamdar, and A. Tiwari, "Carboxymethyl chitosan and its applications," Advanced Materials Letters, vol. 1, no. 1, pp. 11-33, 2010.
[57] R. Wang, K. G. Neoh, Z. Shi, E. T. Kang, P. A. Tambyah, and E. Chiong, "Inhibition of Escherichia coli and Proteus mirabilis adhesion and biofilm formation on medical grade silicone surface," Biotechnology and bioengineering, vol. 109, no. 2, pp. 336-345, 2012.
[58] Z. Li, X. P. Zhuang, X. F. Liu, Y. L. Guan, and K. De Yao, "Study on antibacterial O-carboxymethylated chitosan/cellulose blend film from LiCl/N, N-dimethylacetamide solution," Polymer, vol. 43, no. 4, pp. 1541-1547, 2002.
[59] K. M. Koczkur, S. Mourdikoudis, L. Polavarapu, and S. E. Skrabalak, "Polyvinylpyrrolidone (PVP) in nanoparticle synthesis," Dalton transactions, vol. 44, no. 41, pp. 17883-17905, 2015.
[60] H. Folttmann and A. Quadir, "Polyvinylpyrrolidone (PVP)—one of the most widely used excipients in pharmaceuticals: an overview," Drug Deliv Technol, vol. 8, no. 6, pp. 22-27, 2008.
[61] X. Liu, W. Tong, Z. Wu, and W. Jiang, "Poly (N-vinylpyrrolidone)-grafted poly (dimethylsiloxane) surfaces with tunable microtopography and anti-biofouling properties," RSC advances, vol. 3, no. 14, pp. 4716-4722, 2013.
[62] A. Kyrychenko, O. M. Korsun, I. I. Gubin, S. M. Kovalenko, and O. N. Kalugin, "Atomistic simulations of coating of silver nanoparticles with poly (vinylpyrrolidone) oligomers: Effect of oligomer chain length," The Journal of Physical Chemistry C, vol. 119, no. 14, pp. 7888-7899, 2015.
[63] H. Li et al., "Synthesis and catalytic performance of polydopamine supported metal nanoparticles," Scientific reports, vol. 10, no. 1, pp. 1-7, 2020.
[64] V. Ball, "Polydopamine nanomaterials: recent advances in synthesis methods and applications," Frontiers in bioengineering and biotechnology, vol. 6, p. 109, 2018.
[65] B. Liu, X. Han, and J. Liu, "Iron oxide nanozyme catalyzed synthesis of fluorescent polydopamine for light-up Zn 2+ detection," Nanoscale, vol. 8, no. 28, pp. 13620-13626, 2016.
[66] H. Cao et al., "Pt@ polydopamine nanoparticles as nanozymes for enhanced photodynamic and photothermal therapy," Chemical Communications, vol. 57, no. 2, pp. 255-258, 2021.
[67] Y. Qi, L. Zhu, C. Gao, and J. Shen, "A novel nanofiltration membrane with simultaneously enhanced antifouling and antibacterial properties," RSC Advances, vol. 9, pp. 6107-6117, 02/19 2019.
[68] S. Lin et al., "Copper tannic acid coordination nanosheet: a potent nanozyme for scavenging ROS from cigarette smoke," Small, vol. 16, no. 27, p. 1902123, 2020.
[69] Z. Ge, B. Wu, T. Sun, and B. Qiao, "Laccase-like nanozymes fabricated by copper and tannic acid for removing malachite green from aqueous solution," Colloid and Polymer Science, vol. 299, no. 10, pp. 1533-1542, 2021.
[70] H. I. Abdel and M. S. Mansour, "Polyphenols: Properties, occurrence, content in food and potential effects," Environmental Science and Engineering, vol. 6, pp. 232-61, 2017.
[71] L. Weng, P. Rostamzadeh, N. Nooryshokry, H. C. Le, and J. Golzarian, "In vitro and in vivo evaluation of biodegradable embolic microspheres with tunable anticancer drug release," Acta biomaterialia, vol. 9, no. 6, pp. 6823-6833, 2013.
[72] T. Yamaguchi, H. Takamura, T. Matoba, and J. Terao, "HPLC method for evaluation of the free radical-scavenging activity of foods by using 1, 1-diphenyl-2-picrylhydrazyl," Bioscience, biotechnology, and biochemistry, vol. 62, no. 6, pp. 1201-1204, 1998.
[73] S. Kannan, K. Mohanraj, K. Prabhu, S. Barathan, and G. Sivakumar, "Synthesis of selenium nanorods with assistance of biomolecule," Bulletin of Materials Science, vol. 37, no. 7, pp. 1631-1635, 2014.
[74] I. Karatzas and S. E. Shreve, "Brownian motion," in Brownian motion and stochastic calculus: Springer, 1998, pp. 47-127.
[75] C.-C. Ho and S.-J. Ding, "Dopamine-induced silica–polydopamine hybrids with controllable morphology," Chemical Communications, vol. 50, no. 27, pp. 3602-3605, 2014.
[76] M. Shao et al., "Polydopamine coated hollow mesoporous silica nanoparticles as pH-sensitive nanocarriers for overcoming multidrug resistance," Colloids and Surfaces B: Biointerfaces, vol. 183, p. 110427, 2019.
[77] S. Torres et al., "Biosynthesis of selenium nanoparticles by Pantoea agglomerans and their antioxidant activity," Journal of Nanoparticle Research, vol. 14, no. 11, pp. 1-9, 2012.
[78] W. Zhang et al., "Synthesis and antioxidant properties of Lycium barbarum polysaccharides capped selenium nanoparticles using tea extract," Artificial cells, nanomedicine, and biotechnology, vol. 46, no. 7, pp. 1463-1470, 2018.
[79] A. Wan, Q. Xu, Y. Sun, and H. Li, "Antioxidant activity of high molecular weight chitosan and N, O-quaternized chitosans," Journal of agricultural and food chemistry, vol. 61, no. 28, pp. 6921-6928, 2013.
[80] T. Sun, Q. Yao, D. Zhou, and F. Mao, "Antioxidant activity of N-carboxymethyl chitosan oligosaccharides," Bioorganic & medicinal chemistry letters, vol. 18, no. 21, pp. 5774-5776, 2008.
[81] Z. Guo, R. Xing, S. Liu, Z. Zhong, and P. Li, "Synthesis and hydroxyl radicals scavenging activity of quaternized carboxymethyl chitosan," Carbohydrate Polymers, vol. 73, no. 1, pp. 173-177, 2008.
[82] X. Liu, M. M. Jansman, W. Li, P. Kempen, P. W. Thulstrup, and L. Hosta-Rigau, "Metal–organic framework-based oxygen carriers with antioxidant protection as a result of a polydopamine coating," Biomaterials Science, vol. 9, no. 21, pp. 7257-7274, 2021.
[83] S. Boroumand, M. Safari, E. Shaabani, M. Shirzad, and R. Faridi-Majidi, "Selenium nanoparticles: synthesis, characterization and study of their cytotoxicity, antioxidant and antibacterial activity," Materials Research Express, vol. 6, no. 8, p. 0850d8, 2019.
[84] İ. Gülçin, Z. Huyut, M. Elmastaş, and H. Y. Aboul-Enein, "Radical scavenging and antioxidant activity of tannic acid," Arabian journal of chemistry, vol. 3, no. 1, pp. 43-53, 2010.
[85] J. Field and G. Lettinga, "Toxicity of tannic compounds to microorganisms," in Plant polyphenols: Springer, 1992, pp. 673-692.
[86] E. M. Boyd, "The acute toxicity of tannic acid administered intragastrically," Canadian Medical Association Journal, vol. 92, no. 25, p. 1292, 1965.
[87] V. N. Montesinos, M. Sleiman, S. Cohn, M. I. Litter, and H. Destaillats, "Detection and quantification of reactive oxygen species (ROS) in indoor air," Talanta, vol. 138, pp. 20-27, 2015.
[88] H. Cheng, S. Lin, F. Muhammad, Y.-W. Lin, and H. Wei, "Rationally modulate the oxidase-like activity of nanoceria for self-regulated bioassays," Acs Sensors, vol. 1, no. 11, pp. 1336-1343, 2016.
[89] Z. Chen et al., "Dual enzyme-like activities of iron oxide nanoparticles and their implication for diminishing cytotoxicity," Acs Nano, vol. 6, no. 5, pp. 4001-4012, 2012.
[90] Y. Lin, J. Ren, and X. Qu, "Nano‐gold as artificial enzymes: hidden talents," Advanced materials, vol. 26, no. 25, pp. 4200-4217, 2014.
[91] J. Li, W. Liu, X. Wu, and X. Gao, "Mechanism of pH-switchable peroxidase and catalase-like activities of gold, silver, platinum and palladium," Biomaterials, vol. 48, pp. 37-44, 2015.