Membrane‐Penetrating Carbon Quantum Dots for Imaging Nucleic Acid Structures in Live Organisms

Abstract

The dynamics of DNAa nd RNAs tructures in live cells are important for understanding cell behaviors,s uch as transcription activity,p rotein expression, cell apoptosis,a nd hereditary disease,b ut are challenging to monitor in live organisms in real time.The difficulty is largely due to the lack of photostable imaging probes that can distinguish between DNAand RNA, and more importantly,are capable of crossing multiple membrane barriers ranging from the cell/organelle to the tissue/organ level. We report the discovery of ac ationic carbon quantum dot (cQD) probe that emits spectrally distinguishable fluorescence upon binding with doublestranded DNAa nd single-stranded RNAi nl ive cells,t hereby enabling real-time monitoring of DNAand RNAl ocalization and motion. Asurprising finding is that the probe can penetrate through various types of biological barriers in vitro and in vivo.Combined with standardand super-resolution microscopy, photostable cQDs allowtime-lapse imaging of chromatin and nucleoli during cell division and Caenorhabditis elegans (C.elegans) growth.

Spatiotemporally Monitoring Cell Viability through Programmable Mitochondrial Membrane Potential Transformation by Using Fluorescent Carbon Dots

“…In apoptosis cells with the decrease of mitochondrial membrane potential, MMP‐CDs were migrated from mitochondria to lysosome due to the hydrophilicity and multiple charge of the MMP‐CDs and mitochondrial autophagy (encased in autophagy lysosomes) 22,23. In dead cells with vanished mitochondrial membrane potential, the MMP‐CDs mainly exist in nucleus due to the affinity with DNA 24,25…”

Recent Advances and Sensing Applications of Carbon Dots

“…The resolution of the images is higher than that obtained from total internal reflection fluorescence microscopy. Recently, C dots (<3 nm) functionalized with 4‐carboxybutyl triphenylphosphonium bromide were reported to localize the DNA, RNA, and nucleolus inside cells . Furthermore, time‐lapse images of chromatin and nucleoli during cell division and the growth of Caenorhabditis elegans were obtained when applying super‐resolution microscopy.…”

Chiral Self-Assembly of Porphyrins Induced by Chiral Carbon Dots

“…As a new star in the family of carbon-based nanomaterials, fluorescent carbon dots (CDots) have attracted more and more attention in recent years (Lim et al, 2015). Compared with traditional semiconductor quantum dots and organic dyes, CDots not only maintain the advantages of low toxicity and good biocompatibility of carbon materials, but also have the advantages of good light stability, easy functionalization, low price, and easy large-scale synthesis (Baker and Baker, 2010), that can be applied in optical devices (Tian et al, 2017), biosensors (Feng et al, 2013), drug delivery (Gong et al, 2019), and optical imaging (Han et al, 2019).…”