Carbon
dots (CDs) have been widely studied for their excellent properties.
However, most of the prepared CDs only show strong emission in the
blue to green region, which greatly limits the application of CDs
in the biomedical field. In this report, a new design strategy of
long-wavelength CDs was reported. The orange phenyl-CDs with good
optical properties and biocompatibility were successfully prepared
by changing the substituted group of the o-phenylenediamine
and the main emission band of phenyl-CDs was in the far-red region.
With the increase of polarity, the wavelength of phenyl-CDs red-shifts
and the fluorescence intensity decreases, demonstrating their sensitive
polarity response function. In addition, phenyl-CDs can achieve ultrafast
target imaging of lysosome within 40 s through clathrin-mediated endocytosis.
Finally, phenyl-CDs were successfully applied for monitoring lysosomal
polarity induced by drugs, which is helpful in getting a better understanding
of the physiological and pathological processes of lysosomes. This
report provides an important theoretical basis for the rational design
and precise synthesis of long-wavelength fluorescent CDs.
Wound healing is an essential and complex biological process. Research into its mechanism and factors that influence its effectiveness has led to better treatments. Changes in the microenvironment are demonstrated to affect wound healing. Cell polarity is a significant microenvironment-related parameter that is associated with many physiological and pathological activities. However, dynamic changes in polarity during wound healing have not been investigated. Monitoring cell polarity during wound healing may open up a new avenue for developing better treatments. Here, a method is developed to monitor cell polarity that involved taking advantage of the fascinating optical properties and biocompatibility of carbon dots (CDs). Specifically, near-infrared (NIR) polarity-sensitive N-phenyl-pphenylenediamine (PPh-CDs) are successfully prepared, which exhibit high sensitivity to polarity, with 509-fold stronger fluorescence in dioxane than in water. The PPh-CDs are successfully applied to monitor the changes of lysosomal polarity during starvation conditions. Using this method, dynamic changes of polarity during wound healing of zebrafish are monitored for the first time. Upon an amputation performed at the zebrafish tail, stronger PPh-CDs fluorescence appeared at the wound sites, and the intensity increased for 25 min and then gradually decreased. This report provides an important experimental basis for investigating wound healing by employing polarity-sensitive CDs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.