Design strategies for water-soluble small molecular chromogenic and fluorogenic probes.

This review focuses on classifying different types of long wavelength absorbing BODIPY dyes based on the wide range of structural modification methods that have been adopted, and on tabulating their spectral and photophysical properties. The structure–property relationships are analyzed in depth with reference to molecular modeling calculations, so that the effectiveness of the different structural modification strategies for shifting the main BODIPY spectral bands to longer wavelengths can be readily compared, along with their effects on the fluorescence quantum yield (ΦF) values. This should facilitate the future rational design of red/NIR region BODIPY dyes for a wide range of different applications.

Structural modification strategies for the rational design of red/NIR region BODIPYs

Reactive oxygen (ROS) and nitrogen (RNS) species cause oxidative and nitrosative stresses, respectively. These stresses are implicated not only in diverse physiological processes but also in various pathological processes, including cancer and neurodegenerative disorders. In addition, some ROS and RNS in the environment are pollutants that threaten human health. As a consequence of these effects, sensitive methods, which can be employed to selectively monitor ROS and RNS in live cells, tissues and organisms as well as in environmental samples, are needed so that their biological roles can be understood and their concentrations in environmental samples can be determined. In this review, fluorescent, luminescent and colorimetric ROS and RNS probes, which have been developed since 2011, are comprehensively discussed.

Recent progress in the development of fluorescent, luminescent and colorimetric probes for detection of reactive oxygen and nitrogen species

Two types of carbon dots (C dots) exhibiting respective excitation-independent blue emission and excitation-dependent full-color emissions have been synthesized via a mild one-pot process from chlo...

Carbon Dots with Continuously Tunable Full-Color Emission and Their Application in Ratiometric pH Sensing

Xin Zhou,†,‡ Songyi Lee,† Zhaochao Xu,* and Juyoung Yoon*,† †Department of Chemistry and Nanoscience, Ewha Womans University, Seoul 120-750, Republic of Korea ‡Research Center for Chemical Biology, Department of Chemistry, Yanbian University, Yanjii 133002, People’s Republic of China Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Shahekou, Dalian, Liaoning, People’s Republic of China

Recent Progress on the Development of Chemosensors for Gases.

A lysosome-specific and two-photon fluorescent probe, Lyso-NINO, demonstrates high selectivity and sensitivity toward NO, lower cytotoxicity, and perfect lysosomal localization. With the aid of Lyso-NINO, the first capture of NO within lysosomes of macrophage cells has been achieved using both two-photon fluorescence microscopy and flow cytometry.

A lysosome-targetable and two-photon fluorescent probe for monitoring endogenous and exogenous nitric oxide in living cells.

In the orignial 1,3,5,7-tetraphenyl aza-BODIPY, replacing the phenyl rings with thiophene achieved significant bathochromic shifts. One of the target molecules, DPDTAB, emitting strong NIR fluorescence with a quantum yield of 0.46 in acetonitrile, is a very competitive NIR fluorophore.

Replacing Phenyl Ring with Thiophene: An Approach to Longer Wavelength Aza-dipyrromethene Boron Difluoride (Aza-BODIPY) Dyes

Nitric oxide (NO) is a ubiquitous cellular messenger molecule in the cardiovascular, nervous, and immune systems. Mitochondrion is the main area where endogenous NO is synthesized by inducible NOS enzymes in mammalian cells. Thus, real-time monitoring NO in mitochondria is very meaningful for NO chemical biology. Although a variety of fluorescent probes for NO have been successfully developed, they are not suited for detecting mitochondrial NO because none of them can specifically localize in mitochondria. Herein, Mito-Rh-NO, the first mitochondria-targetable “turn-on” fluorescent probe for NO, has been developed through attaching a triphenylphosphonium to a rhodamine spirolactam. The characteristics of this probe are as following: (1) Mito-Rh-NO exhibits high sensitivity toward NO. In solution, Mito-Rh-NO responds to NO by significant fluorescence enhancement up to 60-fold, and its NO detection limit is as low as 4.0 nM. (2) The NO sensing of Mito-Rh-NO is highly selective, which will not interfere with ...

Targetable Fluorescent Probe for Monitoring Exogenous and Endogenous NO in Mitochondria of Living Cells

Rhodamine derivatives and analogues have been widely used for different super-resolution imaging techniques, including photoactivated localization microscopy (PALM). Among them, rhodamine spirolactams exhibit great superiority for PALM imaging due to a desirable bright-dark contrast during the photochromic switching process. Although considerable attention has been paid to the chemical modifications on rhodamine spirolactams, the on-time of photochromic switching, one of the key characteristics for PALM imaging, has never been optimized in previous developments. In this study, we proposed that simply installing a carboxyl group close to the lactam site could impose an intramolecular acidic environment, stabilize the photoactivated zwitterionic structure, and thus effectively increase the on-time. On the basis of this idea, we have synthesized a new rhodamine spirolactam, Rh-Gly, that demonstrated considerably longer on-time than the other tested analogues, as well as an enhancement of single-molecule brightness, an improvement on signal-to-noise ratio and an enlargement of total collected photons of a single molecule before photobleaching. Finally, super-resolution images of live cell mitochondria stained with Rh-Gly have been obtained with a good temporal resolution of 10 s, as well as a satisfactory localization precision of ∼25 nm. Through self-labeling protein tags, Rh-Gly modified with a HaloTag ligand enabled super-resolution imaging of histone H2B proteins in live HeLa cells; through immunostaining antibodies labeled with an isothiocyanate-substituted Rh-Gly, super-resolution imaging of microtubules was achieved in fixed cells. Therefore, our simple and effective strategy provides novel insight for developing further enhanced rhodamine spirolactams recommendable for PALM imaging.

Strategy to Lengthen the On-Time of Photochromic Rhodamine Spirolactam for Super-resolution Photoactivated Localization Microscopy

Based on a FRET scaffold bearing BODIPY and TMR fluorophores, a ratiometric fluorescent probe BRP-NO highly sensitive and selective to nitric oxide was developed and employed for imaging intracellular nitric oxide released from NOC13.

Haibo Yu

Papers

A lysosome-targetable and two-photon fluorescent probe for monitoring endogenous and exogenous nitric oxide in living cells.

Replacing Phenyl Ring with Thiophene: An Approach to Longer Wavelength Aza-dipyrromethene Boron Difluoride (Aza-BODIPY) Dyes

Targetable Fluorescent Probe for Monitoring Exogenous and Endogenous NO in Mitochondria of Living Cells

Strategy to Lengthen the On-Time of Photochromic Rhodamine Spirolactam for Super-resolution Photoactivated Localization Microscopy

From a BODIPY–rhodamine scaffold to a ratiometric fluorescent probe for nitric oxide