Fig. 3.
Different structure and composition of nanoparticles in fluorescence biomedical imaging. A: vector type; B: core-shell structure of NP; C: NP as a quencher; D: NP connected with fluorophore and quencher, E: Forster resonance energy transferred imaging NP (yellow arrow: nanoparticle; red arrow: fluorescent dye; blue arrow: ligand; grey arrow: quencher; yellow curve arrow: energy transfer; green curve arrow: excitation light; red curve arrow: emission light; MMP: matrix metalloproteinase).