Ag nanobox/silica/CdTeS quantum dot nanoprobe with photoluminescence emission enhancement for labeling cancer cells

Highlights: • Ag nanobox/silica/CdTeS QD nanoprobe was synthetized. • The strongest fluorescence signal obtained as SiO₂ shell tuned to 10 nm. • An 4.5-fold enhancement was realized, compared with the bare QDs. • The nanoprobe realized the labeling to cancer cells. Ag nanobox/silica/quantum dot (QD) nanoprobe was synthesized by using a hydrothermal method to investigate the interaction between Ag nanobox and CdTeS QDs for the first time. Finite-difference time domain method was used to compare the optical behavior of Ag nanobox with Ag nanosquare. The comparison demonstrated that the Ag nanobox had excellent optical characteristics. In the nanoprobe, the silica shell was used to adjust the distance between the Ag nanobox and CdTeS QDs. A 4.5-fold increase in the fluorescence intensity of CdTeS QDs was achieved based on the local surface plasmon resonance (LSPR) of Ag nanobox. The Ag nanobox/silica/CdTeS QD nanoprobe was used to label cancer cells, thereby indicating that the nanoprobe was a suitable and excellent fluorescence probe.