شناسایی توکسوئید کزاز با نانو زیست حسگر مغناطیسی آهن
محورهای موضوعی : بیوفیزیکفرزانه کارخانه یوسفی 1 , احمد مولایی راد 2 * , زیبا کریمی صدر 3 , عادله دیوسالار 4 , پروانه مقامی 5
1 - پژوهشکده جامع علوم و فناوریهای همگرا، دانشگاه آزاد اسلامی واحد علوم و تحقیقات تهران، تهران، ایران
2 - پژوهشکده جامع علوم و فناوریهای همگرا، دانشگاه آزاد اسلامی واحد علوم و تحقیقات تهران، تهران، ایران
3 - پژوهشکده جامع علوم و فناوریهای همگرا، دانشگاه آزاد اسلامی واحد علوم و تحقیقات تهران، تهران، ایران
4 - گروه علوم سلولی و مولکولی، دانشکده علوم زیستی، دانشگاه خوارزمی، تهران، ایران
5 - پژوهشکده جامع علوم و فناوریهای همگرا، دانشگاه آزاد اسلامی واحد علوم و تحقیقات تهران، تهران، ایران
کلید واژه: نانوذرات اکسید آهن, تترا اتوکسی سیلان, 3- آمینوپروپیل تترا اتوکسی سیلان, سیلانیزاسیون, سل-ژل, آنتی بادی مونوکلونال توکسوئید کزاز.,
چکیده مقاله :
مقدمه: بیوپروب ها یا کاوشگرهای زیستی مبتنی بر نانوذرات اکسید آهن به دلیل واکنش پذیری بالا، زیست سازگاری، هزینه تولید پایین و جداسازی نمونه تحت میدان مغناطیسی، گزینه خوبی برای تشخیص زودهنگام بیماری های کشنده و عفونی مانند کزاز هستند. هدف ازین پژوهش شناسایی توکسوکوئیدهای کزاز با نانو زیست حسگرهای مغناطیسی آهن است.
مواد و روشها: ابتدا گروه‌های سیلان، با استفاده از هیدرولیز تترااتوکسی سیلان (TEOS) بر روی سطح نانوذرات اکسید آهن پوشش داده شده و گروه‌های NH2 با استفاده از 3-آمینوپروپیل تری‌اتوکسی سیلان (APTES) بر روی سطح نانوذرات سیلانی شده، تولید شدند و آنتی بادی بر روی سطح نانوذرات سیلانی شده تثبیت شد. در ادامه، سیلانیزاسیون و آنتی بادی تثبیت شده با استفاده از تکنیک FT-IR، EDX، VSM، SRB مورد بررسی قرار گرفت. در نهایت، طیف‌سنجی UV/vis، فلورسانس، آزمایش آگلوتیناسیون و ELISA برای عملکرد و ویژگی حسگر زیستی به کار گرفته شد.
یافته ها: نتایج طیف‌سنجی FT-IR نشان داد که پیوندهای Si-O-Si و Si-O-Fe و گروه‌های کلر TCT و آمین آنتی‌بادی‌های ضد سم کزاز روی سطح نانوذرات اکسید آهن تشکیل شده‌اند. وجود عناصر Si، N و C در آنالیز EDX، سیلانیزاسیون نانوذرات اکسید آهن را تایید می‌کند. از طرفی، نتایج VSM نشان داد که مقدار نانوذرات مغناطیسی پس از کونژوگه شدن برای کاربردهای بیولوژیکی کافی است. تثبیت آنتی بادی بر روی نانوذرات باعث افزایش شدت جذب در طیف سنج uv/vis شد. نتایج نشان داد که شدت فلورسانس این نانوپروب زیستی در حضور 10 نانوگرم در میلی لیتر افزایش می یابد. همچنین نانوبیوپروب ها در حضور آنتی ژن توکسوئید کزاز به صورت آگلومرا مشاهده شدند. وجود آنتی ژن کزاز باعث تشکیل کمپلکس آنتی ژن آنتی ژن-نانوبیوپروب شد. شناسایی این کمپلکس توسط آنتی بادی متصل به HRP، ویژگی نانوبیوپروب را تایید می کند.
نتیجه گیری: نانوبیوپروب مغناطیسی کزاز با محدودیت تشخیصی 10 نانوگرم در میلی لیتر آنتی ژن کزاز، در مدت زمان کوتاهی می تواند ابزار خوبی را برای دستگاه های LOC و تراشه های میکروسیال فراهم کند.
Introduction
Iron oxide nanoparticle-based bioprobes are highly suitable platforms for the early diagnosis of fatal infectious diseases like tetanus, due to their exceptional reactivity, biocompatibility, cost-effective production, and straightforward isolation under a magnetic field. This research focused on employing magnetic iron nanobiosensors to detect tetanus toxoid.
Materials and Methods: The initial step involved coating iron oxide nanoparticles with silane groups through the hydrolysis of tetraethoxysilane (TEOS). This was followed by the introduction of amine (NH₂) groups onto the silanized surface using (3-aminopropyl)triethoxysilane (APTES). Antibodies were subsequently immobilized onto the modified nanoparticles. The success of the silanization and antibody conjugation procedures was analyzed using Fourier-transform infrared (FT-IR) spectroscopy, Energy-dispersive X-ray spectroscopy (EDX), Vibrating-sample magnetometry (VSM), and the Sulforhodamine B (SRB) test. The biosensor's performance and specificity were ultimately assessed through UV/Vis spectroscopy, fluorescence spectroscopy, an agglutination assay, and an enzyme-linked immunosorbent assay (ELISA).
Results: FT-IR spectroscopy verified the successful formation of Si-O-Si and Si-O-Fe bonds, alongside the presence of TCT chloride and amine groups originating from the anti-tetanus toxin antibodies on the nanoparticle surface. EDX analysis corroborated the silanization process by identifying the existence of silicon (Si), nitrogen (N), and carbon (C) elements. VSM results confirmed that the magnetic saturation value of the nanoparticles remained adequately high for biological uses post-conjugation. Antibody immobilization resulted in an increased absorption intensity observed via UV/Vis spectroscopy. Fluorescence data indicated a rise in the signal intensity of the nanobioprobe when exposed to an antigen concentration of 10 ng/mL. Furthermore, the nanobioprobes exhibited agglomeration in the presence of the tetanus toxoid antigen. The specific formation of an antigen-antibody-nanoprobe complex was confirmed by detection with an HRP-conjugated antibody, validating the high specificity of the nanobioprobe.
Conclusion: The developed magnetic nanobioprobe for tetanus detection, which has a detection limit of 10 ng/mL for the target antigen, presents an efficient solution for integration into Lab-on-a-Chip (LOC) devices and microfluidic chips, enabling rapid diagnostics.
1. Jafari M, Mahdavi Ortakand M, Safai Javan S. Optimization of the green synthesis of silver nanoparticles using aqueous extract of black cumin fruit by Taguchi method. Biological knowledge of Iran. 2016 Nov 21;11(4):1-1.
2. Cortina ME, Moya SE, Sinha S, Pividori MI. Electrochemical magnetic microbeads-based biosensor for point-of-care serodiagnosis of infectious diseases. Biosensors and Bioelectronics. 2016;80:24-33. DOI:10.1016/j.bios.2016.01.021
3. Ravalli A, Marrazza G. Gold and magnetic nanoparticles-based electrochemical biosensors for cancer biomarker determination. Journal of nanoscience and nanotechnology. 2015;15(5):3307-19. DOI:10.1166/jnn.2015.10011
4. Quesada-González D, Merkoçi A. Nanomaterial-based devices for point-of-care diagnostic applications. Chemical Society Reviews. 2018;47(13):4697-709. DOI:10.1039/c7cs00837f
5. Andrews RJ. Nanotechnology: Managing Molecules for Modern Medicine. In: The Modern Hospital. Springer; 2019. p. 133-43. DOI:10.1007/978-3-030-01394-3_11
6. Dodi G, Hritcu D, Dragan M, Popa MI. Hexagonal-shaped aminosilane magnetite nanoparticles: Preparation, characterization and hybrid film deposition. Colloids and Surfaces A: Physicochemical and Engineering Aspects. 2018;542:21-30. DOI:10.1016/j.colsurfa.2018.01.034
7. Anirudhan TS, Divya PL, Nima J. Synthesis and characterization of silane coated magnetic nanoparticles/glycidylmethacrylate-grafted-maleated cyclodextrin composite hydrogel as a drug carrier for the controlled delivery of 5-fluorouracil. Materials Science and Engineering: C. 2015;55:471-81. DOI:10.1016/j.msec.2015.05.065
8. Henderson L, Chávez JL, Kim J, Yoon J, Kelly D, Kelley EG, et al. Routes to potentially safer T 1 magnetic resonance imaging contrast in a compact plasmonic nanoparticle with enhanced fluorescence. ACS nano. 2018;12(8):8214-23. DOI:10.1021/acsnano.8b03326
9. Evans BA, Ivantsiv V, Chiu-Lam A, Rinaldi C. Non-monotonicity in the influence of nanoparticle concentration on SAR in magnetic nanoparticle hyperthermia. Journal of Magnetism and Magnetic Materials. 2018;465:559-65. DOI:10.1016/j.jmmm.2018.06.031
10. Ghutepatil P, Sawant S, Koli P, Patil M. APTES (3-aminopropyltriethoxy silane) functionalized MnFe2O4 nanoparticles: a potential material for magnetic fluid hyperthermia. Chemical Papers. 2019;73(9):2189-97. DOI:10.1007/s11696-019-00773-2
11. Schwaminger SP, Blank-Shim SA, Scheifele I, Fraga-García P, Berensmeier S. Magnetic one-step purification of his-tagged protein by bare iron oxide nanoparticles. ACS omega. 2019;4(2):3790-9. DOI:10.1021/acsomega.8b03461
12. Zhou Y, Wang CY, Chen Y, Li Y, Liu Y. Selective binding, magnetic separation and purification of histidine-tagged protein using biopolymer magnetic core-shell nanoparticles. Protein Expression and Purification. 2018;144:5-11. DOI:10.1016/j.pep.2017.11.005
13. Ghahari S, Ghahari S, Nematzadeh GA. Magnetic nano fluids for isolation of genomic DNA and total RNA from various prokaryote and eukaryote cells. Journal of Chromatography B. 2018;1102:125-34. DOI:10.1016/j.jchromb.2018.10.022
14. Oberacker P, Stepper P, Bond DM, Höhn S, Focken J, Meyer V, et al. Bio-On-Magnetic-Beads (BOMB): Open platform for high-throughput nucleic acid extraction and manipulation. PLoS biology. 2019;17(1):e3000107. DOI:10.1371/journal.pbio.3000107
15. Wei X, Wang Y, Chen J, Liu Y, Tang J, Lan Q. Magnetic nanoparticle-based automatic chemiluminescent enzyme immunoassay for golgi protein 73 and the clinical assessment. Journal of Nanoscience and Nanotechnology. 2019;19(4):1971-7. DOI:10.1166/jnn.2019.16294
16. Ivanov AV, Safenkova IV, Zherdev AV, Dzantiev BB. Recombinase polymerase amplification combined with a magnetic nanoparticle-based immunoassay for fluorometric determination of troponin T. Microchimica Acta. 2019;186(8):1-9. DOI:10.1007/s00604-019-3580-9
17. Nakhjavani SA, Afsharan H, Khalilzadeh B, Ghahremani MH, Carrara S, Omidi Y. A highly sensitive and reliable detection of CA15-3 in patient plasma with electrochemical biosensor labeled with magnetic beads. Biosensors and Bioelectronics. 2018;122:8-15. DOI:10.1016/j.bios.2018.09.041
18. Sharma PP, Albisetti E, Massetti M, Scolari M, La Torre C, Monticelli M, et al. Integrated platform for detecting pathogenic DNA via magnetic tunneling junction-based biosensors. Sensors and Actuators B: Chemical. 2017;242:280-7. DOI:10.1016/j.snb.2016.11.059
19. Xianyu Y, Wang Q, Chen Y. Magnetic particles-enabled biosensors for point-of-care testing. TrAC Trends in Analytical Chemistry. 2018;106:213-24. DOI:10.1016/j.trac.2018.07.009
20. Wang T, Zhou Y, Lei C, Lei J, Yang Z. Magnetic impedance biosensor: A review. Biosensors and Bioelectronics. 2017;90:418-35. DOI:10.1016/j.bios.2016.10.031
21. Peterson RD, Chen W, Cunningham BT, Andrade JE. Enhanced sandwich immunoassay using antibody-functionalized magnetic iron-oxide nanoparticles for extraction and detection of soluble transferrin receptor on a photonic crystal biosensor. Biosensors and Bioelectronics. 2015;74:815-22. DOI:10.1016/j.bios.2015.07.050
22. Kyprianou D, Guerreiro AR, Nirwan VP, Al Lawati A, Piletsky SA, Canfarotta F. Development of optical immunosensors for detection of proteins in serum. Talanta. 2013;103:260-6. DOI:10.1016/j.talanta.2012.10.036
23. Sanaeifar N, Rabiee M, Abdolrahim M, Tahriri M, Vashaee D, Tayebi L. A novel electrochemical biosensor based on Fe3O4 nanoparticles-polyvinyl alcohol composite for sensitive detection of glucose. Analytical Biochemistry. 2017;519:19-26. DOI:10.1016/j.ab.2016.12.006
24. del Hierro I, Perez Y, Fajardo M. Silanization of Iron Oxide Magnetic Nanoparticles with ionic liquids based on amino acids and its application as heterogeneous catalysts for Knoevenagel condensation reactions. Molecular Catalysis. 2018;450:112-20. DOI:10.1016/j.mcat.2018.03.011
25. Zhu N, Ji H, Yu P, Niu J, Farooq MU, Akram MW, et al. Surface modification of magnetic iron oxide nanoparticles. Nanomaterials. 2018;8(10):810. DOI:10.3390/nano8100810
26. Nikje MM, Sarchami L, Rahmani L. Fabrication of 2-chloropyridine-functionalized Fe3O4/amino-silane core--shell nanoparticles. International Journal of Nanoscience and Nanotechnology. 2015;11(1):39-44.
27. Maisanaba S, Pichardo S, Puerto M, Gutiérrez-Praena D, Cameán AM, Jos Á. Development, characterization and cytotoxicity of novel silane-modified clay minerals and nanocomposites intended for food packaging. Applied Clay Science. 2017;138:40-7. DOI:10.1016/j.clay.2016.12.038
28. Patra S, Roy E, Madhuri R, Sharma PK. Fast and selective preconcentration of europium from wastewater and coal soil by graphene oxide/silane@ Fe3O4 dendritic nanostructure. Environmental science & technology. 2015;49(10):6117-26. DOI:10.1021/acs.est.5b01013
29. Villegas-Serralta E, Sánchez-Ramírez JF, Talavera-Pech WA, Reyes-López SY, Zavala-Padilla G, Pérez-Campos EL. Detection of HER2 through antibody immobilization is influenced by the properties of the magnetite nanoparticle coating. Journal of Nanomaterials. 2018;2018. DOI:10.1155/2018/9082067
30. Jamshaid T, Neto ETT, Eissa MM, Zine N, Kunita MH, El-Salhi AE, et al. Magnetic particles: From preparation to lab-on-a-chip, biosensors, microsystems and microfluidics applications. TrAC Trends in Analytical Chemistry. 2016;79:344-62. DOI:10.1016/j.trac.2015.10.022
31. Finkelstein P, Teisch L, Allen CJ, Ruiz G. Tetanus: A potential public health threat in times of disaster. Prehospital and Disaster Medicine. 2017;32(3):339-42. DOI:10.1017/S1049023X17000061
32. Hassel B. Tetanus: pathophysiology, treatment, and the possibility of using botulinum toxin against tetanus-induced rigidity and spasms. Toxins. 2013;5(1):73-83. DOI:10.3390/toxins5010073
33. Melville-Smith ME, Seagroatt VA, Watkins JT. A comparison of enzyme-linked immunosorbent assay (ELISA) with the toxin neutralization test in mice as a method for the estimation of tetanus antitoxin in human sera. Journal of biological standardization. 1983;11(2):137-44. DOI:10.1016/s0092-1157(83)80034-7
34. Metz B, van den Dobbelsteen G, van der Pol L, van de Waterbeemd B, van der Ley P, Beuvery C, et al. Physicochemical and immunochemical assays for monitoring consistent production of tetanus toxoid. Biologicals. 2013;41(4):231-7. DOI:10.1016/j.biologicals.2013.03.001
35. Sovaran R, Rahimian M, Habiba A. Preparation of biodegradable magnetic nanoparticles containing insulin for use in oral drug delivery. Biological knowledge of Iran. 2010 Aug 23;5(2):1-1.
36. Hamidi F, Hadjmohammadi MR, Aghaie AB. Ultrasound-assisted dispersive magnetic solid phase extraction based on amino-functionalized Fe3O4 adsorbent for recovery of clomipramine from human plasma and its determination by high performance liquid chromatography: Optimization by experimental design. Journal of Chromatography B. 2017;1063:18-24. DOI:10.1016/j.jchromb.2017.08.018
37. He Y, Chen Q, Xu C, Zhang J, Hu X. Synthesis and characterization of functionalized silica-coated Fe3O4 superparamagnetic nanocrystals for biological applications. Journal of Physics D: Applied Physics. 2005;38(9):1342. DOI:10.1088/0022-3727/38/9/006
38. Bordbar A, Rismanchi M, Oveisi AR, Tangestaninejad S, Zare M. Characterization of modified magnetite nanoparticles for albumin immobilization. Biotechnology research international. 2014;2014. DOI:10.1155/2014/705656
39. Wang P, Zhang G, Li W, Jiao H, Chen Y, Liu X. Entangled Pd complexes over Fe 3 O 4@ SiO 2 as supported catalysts for hydrogenation and Suzuki reactions. Catalysis Science & Technology. 2014;4(5):1333-9. DOI:10.1039/c3cy01071e
40. Saif B, Wang C, Chuan D, Shuang S. Synthesis and characterization of Fe 3 O 4 coated on APTES as carriers for morin-anticancer drug. Journal of Biomaterials and Nanobiotechnology. 2015;6(04):267. DOI:10.4236/jbnb.2015.64025
41. Ranjbakhsh E, Bordbar AK, Abbasi M, Khosropour AR, Shams E. Enhancement of stability and catalytic activity of immobilized lipase on silica-coated modified magnetite nanoparticles. Chemical Engineering Journal. 2012;179:272-6. DOI:10.1016/j.cej.2011.10.098
42. Voigt W. Sulforhodamine B assay and chemosensitivity. In: Chemosensitivity. Springer; 2005. p. 39-48. DOI:10.1385/1-59259-889-7:039
43. Fricker SP. The application of sulforhodamine B as a colorimetric endpoint in a cytotoxicity assay. Toxicology in vitro. 1994;8(4):821-2. DOI:10.1016/0887-2333(94)90073-6
44. Skehan P, Storeng R, Scudiero D, Monks A, McMahon J, Vistica D, et al. New colorimetric cytotoxicity assay for anticancer-drug screening. JNCI: Journal of the National Cancer Institute. 1990;82(13):1107-12. DOI:10.1093/jnci/82.13.1107
45. Van Tonder A, Joubert AM, Cromarty AD. Limitations of the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay when compared to three commonly used cell enumeration assays. BMC research notes. 2015;8(1):1-10. DOI:10.1186/s13104-015-1000-8
46. Vichai V, Kirtikara K. Sulforhodamine B colorimetric assay for cytotoxicity screening. Nature protocols. 2006;1(3):1112-6. DOI:10.1038/nprot.2006.179
47. Hatami R, Jafari AJ, Ebrahimi AA, Ghasemi A. Preparation of amino silane magnetic nanocomposite by the sol--gel process and investigation of its antibacterial activity. Micro & Nano Letters. 2019;14(2):196-201. DOI:10.1049/mnl.2018.5398
48. Xu L, Pan J, Li J, Zhang L, Liu Y. Immobilized Aspergillus niger lipase with SiO2 nanoparticles in sol-gel materials. Catalysts. 2016;6(10):149. DOI:10.3390/catal6100149
49. Dayyani N, Ramazani A, Morsali A. Synthesis and characterization of the first generation of polyamino-ester dendrimer-grafted magnetite nanoparticles from 3-aminopropyltriethoxysilane (APTES) via the convergent approach. Silicon. 2018;10(2):595-601. DOI:10.1007/s12633-016-9493-x
50. Waldron RD. Infrared spectra of ferrites. Physical review. 1955;99(6):1727. DOI:10.1103/PhysRev.99.1727
51. Ma M, Zhang Y, Yu W, Shen HY, Zhang HQ, Gu N. Preparation and characterization of magnetite nanoparticles coated by amino silane. Colloids and Surfaces A: physicochemical and engineering aspects. 2003;212(2-3):219-26. DOI:10.1016/S0927-7757(02)00305-9
52. Mirzaei‐Mosbat M, Ghorbani‐Vaghei R, Sarmast N. One‐pot Synthesis of 4‐Aryl‐NH‐1, 2, 3‐triazoles in Presence of Fe3O4@ SiO2@ Propyl‐HMTA as a New Basic Catalyst. ChemistrySelect. 2019;4(5):1731-7. DOI:10.1002/slct.201803461
53. Demin AM, Pershina AG, Minin AS, Brikunova OY, Murzakaev AM, Abakumov MA, et al. 3-Aminopropylsilane-modified iron oxide nanoparticles for contrast-enhanced magnetic resonance imaging of liver lesions induced by Opisthorchis felineus. International Journal of Nanomedicine. 2016;11:4451. DOI:10.2147/IJN.S113064
54. Nalbandian L, Patrikiadou E, Zaspalis V, Patrikidou A, Hatzidaki E, Papandreou CN. Magnetic nanoparticles in medical diagnostic applications: synthesis, characterization and proteins conjugation. Current Nanoscience. 2016;12(4):455-68. DOI:10.2174/1573413712666160215151548
55. Pavia DL, Lampman GM, Kriz GS, Vyvyan JA. Introduction to spectroscopy. Cengage learning; 2014.
56. Javidparvar AA, Ramezanzadeh B, Ghasemi E. The effect of surface morphology and treatment of Fe3O4 nanoparticles on the corrosion resistance of epoxy coating. Journal of the Taiwan Institute of chemical engineers. 2016;61:356-66. DOI:10.1016/j.jtice.2015.12.020
57. Rouessac F, Rouessac A. Chemical Analysis: Modern Instrumentation Methods and Techniques. Wiley & Sons; 2007.
58. Mashhadizadeh MH, Amoli-Diva M. Drug-carrying amino silane coated magnetic nanoparticles as potential vehicles for delivery of antibiotics. J. Nanomed. Nanotechnol. 2012;3(4):1. DOI:10.4172/2157-7439.1000135
59. Do Kim K, Kim SS, Choa YH, Kim HT. Formation and surface modification of Fe3O4 nanoparticles by co-precipitation and sol-gel method. Journal of Industrial and Engineering Chemistry. 2007;13(7):1137-41.
60. Zhai Y, Wang Z, Wang G, Pei W, Zhang G, Zhang F. Magnetic, fluorescence and transition metal ion response properties of 2, 6-diaminopyridine modified silica-coated fe3o4 nanoparticles. Molecules. 2016;21(8):1066. DOI:10.3390/molecules21081066
61. Huang J, Li Y, Jia X, Song H. Preparation and tribological properties of core-shell Fe3O4@ C microspheres. Tribology International. 2019;129:427-35. DOI:10.1016/j.triboint.2018.08.037
62. Arsalani N, Fattahi H, Nazarpoor M. Synthesis and characterization of PVP-functionalized superparamagnetic Fe3O4 nanoparticles as an MRI contrast agent. Express Polym Lett. 2010;4(6):329-38. DOI:10.3144/expresspolymlett.2010.42
63. Chen Y, Zhang HB, Yang Y, Wang M, Cao A, Yu ZZ. Enhanced electromagnetic interference shielding efficiency of polystyrene/graphene composites with magnetic Fe3O4 nanoparticles. Carbon. 2015;82:67-76. DOI:10.1016/j.carbon.2014.10.031
64. Silva FS, Pereira PM, Silva PA, Lopes-Nunes J, Carvalho J, Oliveira MC, et al. Determination of metabolic viability and cell mass using a tandem resazurin/sulforhodamine B assay. Current protocols in toxicology. 2016;68(1):2.24. 1-2.24. 15. DOI:10.1002/cptx.9
65. Chaki SH, Malek TJ, Chaudhary MD, Tailor JP, Deshpande MP. Magnetite Fe3O4 nanoparticles synthesis by wet chemical reduction and their characterization. Advances in Natural Sciences: Nanoscience and Nanotechnology. 2015;6(3):035009. DOI:10.1088/2043-6262/6/3/035009
66. Villa S, Riani P, Locardi F, Canepa F. Functionalization of Fe3O4 NPs by silanization: use of amine (APTES) and thiol (MPTMS) silanes and their physical characterization. Materials. 2016;9(10):826. DOI:10.3390/ma9100826
67. Kulkarni SA, Sawadh PS, Palei PK. Synthesis and characterization of superparamagnetic Fe 3 O 4@ SiO 2 nanoparticles. Journal of the Korean Chemical Society. 2014;58(1):100-4. DOI:10.5012/jkcs.2014.58.1.100
68. Cheng J, Wang X, Qiu L, Li Y, Marquez M, Ye M, et al. Facile synthesis of chitosan assisted multifunctional magnetic Fe 3 O 4@ SiO 2@ CS@ pyropheophorbide-a fluorescent nanoparticles for photodynamic therapy. New Journal of Chemistry. 2016;40(10):8522-34. DOI:10.1039/c6nj01194e
69. Wang Y, Wang W, Yu L, Tu L, Feng Y, Klein T, et al. An immunomagnetic separation based fluorescence immunoassay for rapid myoglobin quantification in human blood. Analytical Methods. 2016;8(40):7324-30. DOI:10.1039/c6ay01982f
70. Pinheiro PC, Daniel‐da‐Silva AL, Tavares DS, Calatayud MP, Goya GF, Trindade T. Fluorescent magnetic bioprobes by surface modification of magnetite nanoparticles. Materials. 2013;6(8):3213-25. DOI:10.3390/ma6083213
71. Shi D, Sadat ME, Dunn AW, Mast DB. Photo-fluorescent and magnetic properties of iron oxide nanoparticles for biomedical applications. Nanoscale. 2015;7(18):8209-32. DOI:10.1039/c5nr01538c
72. Wiklund M, Hertz HM. Ultrasonic enhancement of bead-based bioaffinity assays. Lab on a Chip. 2006;6(10):1279-92. DOI:10.1039/b609223b
73. Baudry J, Rouzeau C, Goubault C, Robic C, Cohen-Tannoudji L, Koenig A, et al. Acceleration of the recognition rate between grafted ligands and receptors with magnetic forces. Proceedings of the National Academy of Sciences. 2006;103(44):16076-8. DOI:10.1073/pnas.0602761103
74. Reverté L, Prieto-Simón B, Campàs M. New advances in electrochemical biosensors for the detection of toxins: Nanomaterials, magnetic beads and microfluidics systems. A review. Analytica chimica acta. 2016;908:8-21. DOI:10.1016/j.aca.2015.12.035
75. Wang Y, Wang W, Yu L, Wang Y, Zhang Q, Xu H, et al. A colorimetric biosensor using Fe3O4 nanoparticles for highly sensitive and selective detection of tetracyclines. Sensors and Actuators B: Chemical. 2016;236:621-6. DOI:10.1016/j.snb.2016.06.029
76. Park JY, Jeong HY, Kim MI, Park TJ. Colorimetric detection system for Salmonella typhimurium based on peroxidase-like activity of magnetic nanoparticles with DNA aptamers. Journal of Nanomaterials. 2015;2015. DOI:10.1155/2015/527462
77. Lu N, Zhang M, Ding L, Zheng J, Zeng C, Wen Y, et al. Yolk--shell nanostructured Fe 3 O 4@ C magnetic nanoparticles with enhanced peroxidase-like activity for label-free colorimetric detection of H 2 O 2 and glucose. Nanoscale. 2017;9(13):4508-15. DOI:10.1039/c7nr00865h
78. Liu X, Song D, Zhang Q, Tian Y, Zhang H. An optical surface plasmon resonance biosensor for determination of tetanus toxin. Talanta. 2004;62(4):773-9. DOI:10.1016/j.talanta.2003.09.028
79. Golberg A, Yarmush ML, Konry T. Picoliter droplet microfluidic immunosorbent platform for point-of-care diagnostics of tetanus. Microchimica Acta. 2013;180(9):855-60. DOI:10.1007/s00604-013-0993-8