Synthesis of photoluminescent ZnO quantum dots and its application in bioimaging

The applications of zinc oxide (ZnO) nanostructures have gained increasing research interests in the past decades. However, limited progress has been made in developing ZnO NP-based multimodality tumor-imaging agents. This work presented synthesis and in vitro bioimaging effect of ethanol dispersed ZnO quantum dots (QDs). The synthesis of ZnO QDs is based on the water-induced protonation of amines. The synthesis pathway was simple and less cost because the preparation process was under routine conditions (room temperature, atmosphere pressure and neutral pH). The synthesized ZnO QDs (mean diameters of 4.5 nm) exhibited a broad and strong ultraviolet emission peak centered near 385 nm under ultraviolet excitation (λ_ex: 325 nm). The results of fourier transform infrared (FTIR) spectra indicated that the surface of ZnO nanocluster were capped by amine/PVP, and formed ZnO@amine/PVP core-shell. The unanticipated bright blue fluorescence signals were generated when the ZnO QDs entered into the bacterial and cancer cells. This raised the possibility that ZnO QDs can be used for fluorescence bio-imaging.