Old trees bloom new flowers, lysosome targeted near-infrared fluorescent probe for ratiometric sensing of hypobromous acid in vitro and in vivo based on Nile red skeleton.

Hypobromous acid (HOBr), one of the significant reactive oxygen species (ROS) that acts as an important role in human immune system, however the increasing level of HOBr in human body can cause the disorder of eosinophils (EPO), leading to oxidative stress in organelles, and further causing a series of diseases. In this study, a ratiometric fluorescent probe DMBP based on Nile red skeleton was developed to detect HOBr specifically by the electrophilic substitution with HOBr. DMBP emits near-infrared (NIR) fluorescence at 653 nm, after reacting with HOBr, the emission wavelength of DMBP shifted blue and a new peak appeared at 520 nm, realizing a ratiometric examination of HOBr with a limit of detection of 89.00 nM. Based on its sensitive and specific response to HOBr, DMBP was applied in the visual imaging of HOBr in HepG2 cells and zebrafish. Foremost, probe DMBP has excellent lysosome targeting ability and NIR emission reduced the background interference of biological tissues, providing a potential analytical tool to further investigate the role of HOBr in lysosome.

Advancements of carbon dots: From the perspective of medicinal chemistry.

Carbon dots (CDs) exhibit great potential in medicinal chemistry due to its excellent optical properties, biocompatibility and scalability, which have attracted significant interest. Based on their specific synthesis and modification, this review provided an overview of the evolution of the synthesis of CDs and reviewed the discovery and development of their optical properties. This review examines recent advances of CDs in medicinal chemistry, with a particular focus on the use of CDs as drugs and carriers for photodynamic and photothermal therapies in the field of neurological disorders, cancer, bacterial, viral, and further in combination with imaging for diagnostic and therapeutic integration. Finally, this review addresses the challenges and limitations of CDs in medicinal chemistry. This review provides a comprehensive overview of the development process of CDs and their applications in various aspects of medicinal chemistry, thereby offers insights to the development of CDs in the field of medicinal chemistry.

Molecular engineering of benzenesulfonyl analogs for visual hydrogen polysulfide fluorescent probes based on Nile red skeleton.

Hydrogen polysulfide (H2Sn, n > 1) has a valuable function in various aspects of biological regulation. Therefore, it is of great significance to realize the visual monitoring of H2Sn levels in vivo. Herein, a series of fluorescent probes NR-BS were constructed by changing types and positions of substituents on the benzene ring of benzenesulfonyl. Among them, probe NR-BS4 was optimized due to its wide linear range (0 âˆ¼ 350 µM) and little interference from biothiols. In addition, NR-BS4 has a broad pH tolerance range (pH = 4 âˆ¼ 10) and high sensitivity (0.140 µM). In addition, the PET mechanism of probe NR-BS4 and H2Sn was demonstrated by DFT calculations and LC-MS. The intracellular imaging studies indicate that NR-BS4 can be successfully devoted to monitor the levels of exogenous and endogenous H2Sn in vivo.