Treatment of TiO2 with COOH-functionalized germanium nanoparticles to enhance the photocurrent of dye-sensitized solar cells

Insight into the Effect of Ligands on the Optical Properties of Germanium Quantum Dots and Their Applications in Persistent Cell Imaging

Germanium quantum dots (GeQDs) show unique advantages in fluorescence applications due to their large quantum confinement effect and excellent biocompatibility. However, GeQDs are confronted with difficulty in accurately controlling the fluorescence emission. This defect brings challenges to understanding the fluorescence mechanism and limits the potential applications of GeQDs. In this paper, a series of GeQDs with the average diameter of about 2.6 nm modified with different ligands were synthesized by the chemical reduction method. The fluorescence emission of GeQDs can be changed from blue to yellow-green through adjusting the surface ligands. The influence of surface ligands on the fluorescence emission of GeQDs was thoroughly investigated by experimental and theoretical calculations. Furthermore, the synthesized GeQDs exhibit good biocompatibility and photostability and can act as high-performance fluorescence probes for long-term fluorescent bioimaging. This work provides a good and deep understanding of the fluorescence mechanism of GeQDs and will facilitate diverse promising applications of GeQDs in the near future.

Synthesis of Fluorescent and Water-Dispersed Germanium Nanoparticles and Their Cellular Imaging Applications

In recent years, Ge nanomaterials have aroused a great deal of attention because of their unique physical and chemical properties. However, the current synthesis methods bear some disadvantages, such as high reaction temperature, dangerous reagents, and inert atmospheres. In this paper, we developed a facile one-step route for preparing fluorescent and water-dispersed germanium nanoparticles (Ge NPs) by utilizing organogermanes as the precursor, operated at mild reactive conditions. The as-synthesized Ge NPs have an average diameter of 2.6 ± 0.5 nm and intense blue-green fluorescence (FL). Furthermore, the as-synthesized Ge NPs show remarkable water dispersibility, favorable biocompatibility, outstanding photostability, excellent storage stability, and low cytotoxicity. More importantly, these Ge NPs can act as a satisfactory FL probe and successfully be applied to cellular imaging of HeLa. The present study offers a simple and moderate strategy for the preparation of Ge NPs and expedites Ge NPs for bioimaging applications.