title: Facile Synthesis of pH-sensitive Germanium Nanocrystals with High Quantum Yield for Intracellular Acidic Compartment Imaging.
abstract: A green-light emitting germanium nanocrystal-based biosensor to monitor lysosomal pH changes is developed. The Ge nanocrystals are synthesized in an aqueous solution with a significantly enhanced photoluminescence quantum yield of 26%. This synthesis involves a facile solution based route which avoided the use of toxic or environmentally unfriendly agents. Importantly, the photoluminescence intensity of the synthesized Ge nanocrystals is particularly sensitive to changes in pH between 5 and 6. When incubated with cultured cells, the nanocrystals are internalized and subsequently translocated via the lysosomal pathway, and the Ge nanocrystals' fluorescence are greatly enhanced, even when the lysosomal pH is only slightly increased. These results reveal that the Ge nanocrystals possess high pH sensitivity compared to a commercially available dye, LysoSensor Green DND-189. The fluorescent properties of the Ge nanocrystals are demonstrated to be dependent on both the crystal form and their surface chemistry. The superior fluorescence properties and bioapplicability of the Ge nanocrystals makes them a promising intracellular bioimaging probe for monitoring various pH-sensitive processes in cells.
authors: CAS Key Laboratory for Biomedical Effects of Nanomaterials & Nanosafety, National Center for Nanoscience and Technology, Beijing, 100190, China; Institute of Optical Imaging and Sensing, Shenzhen Key Laboratory for Minimal Invasive Medical Technologies, Graduate School at Shenzhen, Tsinghua University, Shenzhen, 518055, China.
authors: Feng
authors: F
authors: Li
authors: Jing
authors: J
authors: Wang
authors: Shuqing
authors: S
authors: Sun
authors: Hai
authors: H
authors: Wang
authors: Zhiyong
authors: Z
authors: Tang
authors: Guangjun
authors: G
authors: Nie
mesh_terms: D001562:Benzimidazoles / Q000737:chemistry*; D015374:Biosensing Techniques; D045744:Cell Line, Tumor; D002470:Cell Survival; D005456:Fluorescent Dyes / Q000737:chemistry; D005857:Germanium / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D049449:Luminescence; D008247:Lysosomes / Q000737:chemistry; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry*; D053644:Naphthalimides / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D010777:Photochemistry; D056951:Photoelectron Spectroscopy; D045663:Quantum Dots; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D014466:Ultraviolet Rays
chemical_list: D001562:Benzimidazoles; D005456:Fluorescent Dyes; C000604339:LysoSensor Green DND-189; D053644:Naphthalimides; D005857:Germanium; C040516:germanium oxide; D010100:Oxygen