Designing a sustainable fluorescent targeting probe for superselective nucleus imaging. (15th August 2021)

• Record Type: Journal Article
• Authors: Wang, Liang; Li, Ming; Li, Yongle; Wu, Bin; Chen, Hailong; Wang, Ruining; Xu, Tao; Guo, Huazhang; Li, Weitao; Joyner, Jarin; Shen, Xingcan; Le, Mengying; Vajtai, Robert; Ajayan, Pulickel M.; Ren, Wei; Wu, Minghong
• Is Part Of: Carbon. Volume 180(2021)
• Page Start: 48
• Page End: 55
• Publication Date: 2021-08-15
• Subjects: Graphene quantum dots -- Nitrogen-doping -- Nucleus-targeting imaging -- Fluorescence probes -- Molecular dynamic simulations; Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2021.04.099
• Languages: English
• ISSNs: 0008-6223

Abstract

Abstract: Specific targeting of cell organelles is indispensable for bioimaging and diagnostics but remains a challenge due to the limitation of highly selective fluorescent targeting probes. Herein, we successfully designed a molecular fusion route to controllably synthesize bright orange fluorescent graphene quantum dots (GQDs). The relative nitrogen doping level of the GQDs reached 18.88 at%. The GQDs exhibited long-wavelength excitation fluorescence and photoluminescence (PL) stability. Femtosecond transient absorption spectroscopy elucidated that the sp 2 cluster and the surface state's synergistic effect contributed to the PL. Furthermore, the most alluring discovery was that the GQDs had good biocompatibility and an unprecedented targeting capability for superselective nucleus imaging without staining cell organelles. Molecular dynamics simulations revealed that once the GQDs were transported across the plasma membrane, the higher the N-doping ratio of the GQDs was, and the easier the GQDs penetrated the membrane. The reason may stem from the compatibility of –NH2 with lipid molecules, which is higher than that of –OH. Enriched nitrogen doping in GQDs is beneficial for crossing the cell membrane to the target nucleus. Our findings could provide scientific theory and a technical basis to design nucleus-targeting probes in the future. Graphical abstract: Enriched nitrogen-doping in graphene quantum dots enables a high-selective fluorescent probe for nucleus-targeting imaging. Image 1 Highlights: Bright orange fluorescent GQDs are controllably synthesized by a molecular fusion route. The GQDs exhibited long-wavelength excitation fluorescence and PL stability. The sp 2 cluster and the surface state's synergistic effect contributed to the PL. The GQDs had good biocompatibility and an unprecedented targeting capability for superselective nucleus imaging. Enriched nitrogen doping up to 18.88 at% in GQDs is beneficial for crossing the cell membrane to the target nucleus.