Silica fluorescent nanospheres containing a large amount of quantum dots prepared using liposomes as templates

Abstract

Quantum dot (QD) fluorescent spheres have captivated many scientists because of their many potential applications in biomedical research. In this work, QD nanospheres were prepared using a novel method: incorporating QDs into nano-liposomes and then synthesising a silica shell using a lipid membrane as the template. The results showed that the nanocomposites obtained were spherical in shape, and each nanosphere contained a silica shell and the cores consisted of a large amount of QDs. Ultrathin sections of the spheres showed that the thickness of the silica shell was about 50–60 nm. Because the QD cores were coated with liposome and thick silica shell, the bright field of the silica sphere suspension was close to milk white in colour, which was different from that of the red-coloured QD solution. Although the quantum yield of the silica spheres (2.27%) was lower than that of the QDs (23.52%), these nanospheres still emitted a bright fluorescence, and there was no obvious difference between the fluorescent colour of the nanosphere suspension and the QD solution.