Chu Viet Ha, Chu Anh Tuan, Nguyen Thi Bich Ngoc, Tran Hong Nhung, Nguyen Quang Liem, Vu Thi Kim Lien

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The quantum dots coated by silica  is fluorescence material class with great biocompatibility, low toxicity and water-solubility, that is suitable for bioapplications. This work presents the synthesis of SiO2 coated CdTe/ZnSe (named CdTe) quantum dots (CdTe@SiO2 nanoparticles) via a wet chemmical route called modified Stöber method. The compounds tetraethylorthosilicate (TEOS) has used as precursors, aminopropyltriethoxysilane (APTES) is  as  electric neutralizer, and ammonium hydroxide is used as catalysts. The size of CdTe@SiO2 nanoparticles was estimated about 70 to 150 nm depending on the quantities of H2O, APTEOS, and catalysts. The emission behaviours of SiO2 coated quantum dots was effected by ratio of substances participating in the reaction and synthesis conditions. with the ratio (by volume) of suitable substances: TEOS:solution of QDs:NH4OH:APTES:H2O being 1.5:1.5x10-2:0.8x10-2:4x10-2:3x10-4:5x10-2, the prepared silica nanoparticles containing quantum dots show high fluorescence emission efficiency, the fluorescence intensity is higher than that of uncoated CdTe/ZnSe quantum dots. This is a positive result in the technique of manufacturing luminescent silica nanoparticles containing quantum dots. The results show an ability to use the CdTe@SiO2 nanoparticles for biological application.

Keywords: Stöber method, fluorescence SiO2 nanoparticles, CdTe quantum dots, aminopropyltriethoxysilane precursor, ammonium hydroxide catalysts.


[1] Wolfgang J Parak, Teresa Pellegrino, Christian Plank, Labelling of cells with quantum dots, Nanotechno- logy 16 (2005), R9–R25,
[2] Xiaohu Gao, Lily Yang, John A Petros, Fray F Marshall, Jonathan W Simons and Shuming Nie, In vivo molecular and cellular imaging with quantum dots, Current Opinion in Biotech, 16 (2005) 63-72. 2004.11.003
[3] Aihua Fu, Weiwei Gu, Benjamin Boussert, Kristie Koski, Daniele Gerion, Liberato Manna, Mark Le Gros, Carolyn Larabell and A. Paul Alivisatos, Semiconductor Quantum Rods as Single Molecule Fluorescent Biological LabelsNano Lett. 7(1) (2007) 179–182.
[4] Mark Howarth, Keizo Takao,Yasunori Hayashi, Alice Y. Ting, Targeting quantum dots to surface proteins in living cells with biotin ligase, PNAS 102 (21) (2005) 7583–7588,
[5] M. Dahan, S. Levi, C. Luccardini, P. Rostaing, B. Riveau, A. Triller, Diffusion dynamics of glycine receptors revealed by single-quantum dot tracking, Science 302 (2003) 442-445.
[6] X. Michalet; F.F. Pinaud; L.A. Bentolila; J.M. Tsay, S. Doose, J.J. Li, G. Sundaresan, A.M. Wu; S.S. Gambhir S. Weiss, Quantum Dots for Live Cells, in Vivo Imaging, and Diagnostics, Science 307 (2005) 538−544.
[7] Ung Thi Dieu Thuy, Pham Song Toan, Tran Thi Kim Chi, Dinh Duy Khang, Nguyen Quang Liem, CdTe quantum dots for an application in the life sciences, Adv. Nat. Sci.: Nanosci. Nanotechnol.1(2010) 045009 (5pp).
[8] Thi Dieu Thuy Ung, Thi Kim Chi Tran, Thu Nga Pham, Duc Nghia Nguyen, Duy Khang Dinh, Quang Liem Nguyen, CdTe and CdSe quantum dots: synthesis, characterizations and applications in agriculture, Adv. Nat. Sci.: Nanosci. Nanotechnol. 3 (2012) 043001 (11pp).
[9] Jun Qian, Xin Li, Ming Wei, Xiangwei Gao, Zhengping Xu, Sailing He, Bio-molecule-conjugated fluorescent organically modified silica nanoparticles as optical probes for cancer cell imaging, Optics Express 16 (24) (C) (2008) 19568-19578.
[10] Sehoon Kim, Tymish Y. Ohulchanskyy, Haridas E. Pudavar, Ravindra K. Pandey, Paras N. Prasad, Organically Modified Silica Nanoparticles Co-encapsulating Photosensitizing Drug and Aggregation-Enhanced Two-Photon Absorbing Fluorescent Dye Aggregates for Two-Photon Photodynamic Therapy, J Am Chem Soc. 129(9) (2007) 2669–2675.
[11] A. Burns, H. Ow, U. Wiesner, Fluorescent core–shell silicanano particles: towards “Lab on a Particle” architectures for nanobiotechnology, Chem. Soc. Rev., 35 (2006) 1028–1042. 562b
[12] M.J. Murcia, C.A. Naumann, Biofunctionalization of Nanomaterials, Nanotechnologies for the Life Sciences, Vol. 1, WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim (2005) ISBN: 3-527-31381-8
[13] A. van Blaaderen, A. Vrij, Synthesis and Characterization of Colloidal Monodisperse Organo – Silica Spheres, J. Colloid Interface Sci., 156 (1) (1993). . 1073
[14] T.I. Suratwala, M.L. Hanna, E.L. Miller, P.K. Whitman, I.M. Thomas, P.R. Ehrmann, R.S. Maxwell, A.K. Burnham, Surface chemistry and trimethylsilyl functionalization of Stöber silica sols, J. Non-Cryst. Solids, 316 (2003) 349-363. ISSN: 0022-3039
[15] Francesca Pietra, Relinde J.A. van Dijk - Moes, Xiaoxing Ke, Sara Bals, Gustaaf Van Tendeloo, Celso de Mello Donega, and Daniel Vanmaekelbergh, Synthesis of Highly Luminescent Silica-Coated CdSe/CdS Nanorods, Chem. Mater, 25 (17) (2013) 3427–3434,
[16] X. Gao, J. He, L. Deng, H. Cao, Synthesis and characterization of functionalized rhodamine B – doped silica nanoparticles, Optical Materials, Science Direct, (2009), Vol. 31, 1715-1719. DOI: 10.1016/j.optmat.2008.05.005
[17] H. Jeon, C. Yoon, S. Lee, D.C. Lee, K. Shin and K. Lee, Quantum efficiency of colloidal suspensions containing quantum dot/silica hybrid particles, Nanotechnology 27(43) (2016) 435702.
[18] R. Koole, M.M. van Schooneveld, J. Hilhorst, C. de Mello Donegá, D.C. Hart, A. van Blaaderen, D. Vanmaekelbergh, A. Meijerink, On the inco- rporation mechanism of hydrophobic quantum dots in silica spheres by a reverse microemulsion method, Chem. Mater. 20 (2008) 2503–12.
[19] Nianfang Wang, Sungjun Koh, Byeong Guk Jeong, Dongkyu Lee, Whi Dong Kim, Kyoungwon Park, Min Ki Nam, Kangha Lee, Yewon Kim, Baek-Hee Lee, Kangtaek Lee, Wan Ki Bae and Doh C Lee, Highly luminescent silica-coated CdS/CdSe/CdS nanop- articles with strong chemical robustness and excellent thermal stability”, J. Nanotechnology Volume 28, Number 18 (2017) 185603 (8pp).
[20] Rumiana Bakalova, Zhivko Zhelev, Ichio Aoki, Hideki Ohba, Yusuke Imai, Iwao Kanno, Silica-Shelled Single Quantum Dot Micelles as Imaging Probes with Dual or Multimodality, Anal. Chem. 78 (16) (2006) 5925-5932, ac060412b.
[21] Yunhua Yang, Mingyan Gao, Preparation of Fluorescent SiO2 Particles with Single CdTe Nanocrystal Cores by the Reverse Microemulsion Method, Adv.Mater 17 (2005) 2354-2357. adma.200500403.
[22] T. Nann, P. Mulvaney, Single quantum dots in spherical silica particles, Angew. Chem. Int. Ed. 43(2004) 5393-5396.
[23] Masih Darbandi, Ralf Thomann, Thomas Nann, Single Quantum Dots in Silica Spheres by Microemulsion Synthesis, Chem. Mater. 17 (2005) 5720-5725. 051467h.
[24] Chao Wang, Qiang Ma,Wenchao Dou, Shamsa Kanwal, GuannanWang, Pingfan Yuan, Xingguang Su, Synthesis of aqueous CdTe quantum dots embedded silica nanoparticles and their applications as fluorescence probes, Talanta 77 (4) (2009) 1358–1364. ISSN: 0039 – 9140.
[25] Yoshio Kobayashi, Takuya Nozawa, Tomohiko Nakagawa, Kohsuke Gonda, Motohiro Takeda, Noriaki Ohuchi, Atsuo Kasuya, Direct coating of quantum dots with silica shell, J Sol-Gel Sci Technol. 55 (2010) 79–85. 10.1007/s10971-010-2218-5.
[26] D.A.H. Hanaor, M. Michelazzi, C. Leonelli, C. C. Sorrell, The effects of carboxylic acids on the aqueous dispersion and electrophoretic deposition of ZrO2, Journal of the European Ceramic Society 32 (1) (2012) 235–244. 10.1016/j.jeurceramsoc.2011.08.015
[27] Ning Liu and Ping Yang, Highly luminescent hybrid SiO2-coated CdTe quantum dots: synthesis and properties, J.Luminescence 28 (2013) 542–5.