This work presents the synthesis of CdSe/CdS and CdSe/CdS/SiO2 nanoparticles via wet chemical method for the purpose of preparing fluorescence SiO2 nanoparticles. The CdSe/CdS nanoparticles have been synthesized directly in an aqueous solution using citrate as the surfactant agent. | JOURNAL OF SCIENCE OF HNUE DOI Mathematical and Physical Sci. 2015 Vol. 60 No. 7 pp. 75-80 This paper is available online at http SYNTHESIS OF CdSe CdS AND CdSe CdS SiO2 NANOPARTICLES VIA WET CHEMICAL METHOD Chu Viet Ha1 Hoang Thi Hang2 Nguyen Thi Bich Ngoc3 Ngo Thi Huong1 Vu Thi Kim Lien1 and Tran Hong Nhung3 1 Faculty of Physics Thai Nguyen University of Education 2 Faculty of Physics Hanoi National University of Education 3 Institute of Physics Vietnam Academy of Science and Technology Abstract. This work presents the synthesis of CdSe CdS and CdSe CdS SiO2 nanoparticles via wet chemical method for the purpose of preparing fluorescence SiO2 nanoparticles. The CdSe CdS nanoparticles have been synthesized directly in an aqueous solution using citrate as the surfactant agent. The CdSe CdS nanoparticles are then coated by a silica shell using tetraethylorthosilicate TEOS and aminopropyltriethoxysilane APTEOS as precursors and ammonium hydroxide as the catalyst. The size of the nanoparticles can be controlled by synthesis conditions. The CdSe CdS nanoparticles in citrate aqueous solution have strong intensity of emission high photostability and quantum yield that is suitable for biological applications. The emission intensity of SiO2 coated quantum dots is remarkable. The CdSe CdS quantum dots-based fluorescence silica nanoparticles exhibit a photostability for a long time during storage. The results show that SiO2 coated quantum dots CdSe CdS SiO2 nanoparticles can be used as biomarkers. Keywords CdSe CdS quantum dots citrate CdSe CdS SiO2 nanoparticles Stober method optical properties. 1. Introduction Semiconductor colloidal nanoparticles quantum dots have emerged as a new class of fluorescent probe for in vivo biomolecular and cellular imaging because they are highly photo-stable with broad absorption spectra narrow size-tunable emission spectra remarkably resistant photobleaching can span the light spectrum from the
