A facile way to fabricate CdSe quantum dots coated with silica and the fluorescence property

Good quality quantum dots (QDs) CdSe were prepared with a novel and non-TOP method. Quantum dots with different sizes ranging from 2 to 5 nm could be obtained by removing aliquots of reaction solution at different time intervals. The quantum dots CdSe (core) -silica (shell) was fabricated by a microemulsion method. Transmission electron microscopy (TEM) images confirmed the well monodispersed QDs and the silica shell around CdSe core respectively. UV-Vis absorption and photoluminescence spectra clearly indicated that both the original QDs and the silica-coated QDs had good fluorescence properties. The quantum dots coated with silica shell are water-soluble and less toxic (due to the silica shell), which are anticipated as fluorescent probes for biosensing and imaging applications such as tumor detection of pre-cancers.