A bifunctional fluorescent probe for dual-channel detection of HO and HOCl in living cells.

Hydrogen peroxide (HO) and hypochlorous acid (HOCl) are critical reactive oxygen species (ROS) that play significant roles in regulating oxidative stress, closely tied to various human diseases. However, investigating their interplay within living cells has been challenging due to the lack of effective tools for simultaneous discrimination. Herein, we present a bifunctional fluorescent probe, PTZ-H-H, capable of simultaneously detecting HO and HOCl in living cells via two distinct fluorescence channels.

Manipulating Cation-π Interactions of Reader Proteins in Living Cells with Genetic Code Expansion.

Despite tremendous success in understanding the chemical nature and the importance of cation-π interactions in a range of biological processes, particularly in epigenetic regulation, the design and synthesis of stronger cation-π interactions in living cells remain largely elusive. Here, we design several electron-rich Trp derivatives and incorporate them into histone methylation reader domains to enhance the affinity of the reader domains for histone methylation marks via cation-π interactions in living cells. We show that this site-specific Trp replacement strategy is generally applicable for the engineering of high-affinity reader domains for the major histone H3 trimethylation marks, such as H3K4me3, H3K9me3, H3K27me3, and H3K36me3, with high specificity.

A fluorescent probe based on reversible Michael addition-elimination reaction for the cycle between cysteine and HO.

Cysteine oxidation by HO, generating either cysteine sulfenic acid (CSOH) or disulfide (CSSC), is involved in redox homeostasis and signaling. Compared with quantification of the cysteine content, monitoring the cysteine dynamics in real-time, in particular, takes on even greater importance. However, existing fluorescent probes suffer from low specificity or irreversible recognition mechanisms.

An Endoplasmic Reticulum-Targeted Ratiometric Fluorescent Probe for the Sensing of Hydrogen Sulfide in Living Cells and Zebrafish.

Hydrogen sulfide (HS) is an endogenous gaseous signaling molecule in many physiological processes. Relevant investigations indicated that HS plays a cytoprotective effect under endoplasmic reticulum stress. Currently, it is still a challenge to design effective methods for ratio detection of endoplasmic reticulum HS.

Highly Sensitive and Selective Detection of Heparin in Serum Based on a Long-Wavelength Tetraphenylethylene-Cyanopyridine Aggregation-Induced Emission Luminogen.

A positively charged aggregation-induced emission luminogen (AIEgen), , was constructed by linking a pyridyl cation to tetraphenylethylene (TPE) via a cyanoethylene bond. can realize the identification of heparin (Hep) by aggregating with negatively charged Hep via electrostatic interactions. Upon addition of Hep, exhibited 36-fold fluorescence enhancement in less than 5 s, exhibiting quick and sensitive response to Hep with a low detection limit down to 4 nM.

Revealing the redox status in endoplasmic reticulum by a selenium fluorescence probe.

As an important organelle, the endoplasmic reticulum (ER) participates in the synthesis and secretion of various proteins, glycogen, lipids and cholesterol in eukaryotic cells. In this work, an endoplasmic reticulum-targeted reversible fluorescent probe (ER-Se) was designed and synthesized. The probe, based on a selenide group, shows high sensitivity and good selectivity toward HClO (LOD = 0.

A sensitive ratiometric fluorescent probe for quantitive detection and imaging of alkaline phosphatase in living cells.

We report a sensitive fluorescence probe Ratio-ALP for in vivo ratiometric imaging of alkaline phosphatase (ALP). The probe was designed by conjugating a naphthalimide with a phosphate group as the responsive moiety for enzymatic reactions. The fluorescence intensity ratio displayed a linear relationship against the concentration of ALP in the concentration range from 0 to 200 U/L, its LOD is as low as 0.