Preparation Of Gold-Carbon Quantum Dot Probes And Application Of Organelle Imaging

Owing to the excellent properties such as adjustable emission spectrum,good biocompatibility and ease of functionalization,carbon quantum dots have become one of the promising fluorescent nanomaterials in the biomedical field.However,the microscopic scale of life or physiological activity is always complex and changeable,and simple fluorescent nanomaterial has gradually failed to meet the increasing application requirements.Nanocomposite materials are attracting researchers’ attention due to their integration of many functions and advantages.In this paper,on the basis of carbon quantum dots,a nanocomposite fluorescent material with high biocompatibility was prepared by a microwave assisted method.Due to their tiny size and unique optical properties,gold-carbon quantum dots(GCDs)can be applied to organelle imaging.In this paper,exosome is used as a representative organelle for fluorescence imaging using GCDs.Exosomes are vesicles that carry a large amount of specific proteins and genetic materials.They participate in the transmission of substances and information between cells,which play an important role in the intercellular communication system.In particular,cancer derived exosomes are involved in the invasion and metastasis of cancer.Therefore,conducting fluorescence imaging studies of cancer derived exosomes have important scientific significance for the early diagnosis and treatment of cancer.In the study herein,GCDs were used as fluorophores for the imaging of cancer derived exosomes.The surface of GCDs are modification with specific antibodies that can target cancer derived exosomes,resulting in exosome specific nanoprobes.The nanoprobes can label cancer derived exosomes through an immune reaction,thereby achieving the purpose of exosomes fluorescence imaging.When incubated with live cells,exosomes labeled with the nanoprobes can be taken up by cells.Intracellular imaging experiments confirmed that most of the exosomes endocytosed by cells undergo intracellular biodegradation through the lysosomal pathway,and the manner in which cells take up exosomes and the intracellular distribution of exosomes are not affected by the labeling of GCDs.The results of these fluorescence imaging studies demonstrated that the GCDs-based nanoprobes synthesized in this study can be used to investigate the intracellular behavior of cancer derived exosomes.We believe that GCDs are novel functionalized fluorescent nanomaterials with excellent application prospects.