A bifunctional fluorescent sensor for CCCP-induced cancer cell apoptosis imaging.

The detailed mechanism and the extent of pH/SO2 changes during apoptosis remain unknown. The developed sensor NPCF for SO2 and pH dual detection illustrates that SO2 can reduce the inflammation caused by LPS and the acidification of the environment. The levels of SO2 and pH change during carbonyl cyanide m-chlorophenylhydrazone (CCCP)-induced apoptosis.

Imaging Hg2+-Induced Oxidative Stress by NIR Molecular Probe with "Dual-Key-and-Lock" Strategy.

Mercury (Hg) is considered an extremely toxic heavy metal which is extremely harmful to both the human body and environment. In addition, Hg2+-induced oxidative stress also exerts a crucial role to play in pathophysiological mechanisms of mercury toxicity. Thus, efficient and specific fluorescent probes for imaging Hg2+-induced oxidative stress are necessary. In the present study, we rationally design a novel Hg2+-activated and ICT-based NIR emission fluorescent probe NIR-HO for sequentially monitoring the ONOO- level with a "dual-key-and-lock" strategy. The probe NIR-HO showed rapid response and excellent specificity and sensitivity for the detection of Hg2+ and ONOO- in vitro. Cell imaging demonstrated that Hg2+-induced oxidative stress was involved in ONOO- upregulation. Also, GSH, NAC, and EDTA were employed as excellent detoxifying drugs against Hg2+-induced toxicity. Moreover, the probe NIR-HO was successfully used for imaging Hg2+ and ONOO- in vivo. In brief, NIR-HO provides a simple and powerful approach which can be used to image Hg2+-induced oxidative stress in the pathological environment.

A three-channel fluorescent probe to image mitochondrial stress.

Dual-recognition probes based on one reacting site inevitably encounter competition problems. Here, NPClA, a two-photon fluorescent probe based on a dual-site response for SO2/HOCl, was developed and applied in imaging mitochondrial stress.

Observation of peroxynitrite overproduction in cells during 5-fluorouracil treatment via a ratiometric fluorescent probe.

We describe a colorimetric and fluorescent probe 3a to detect cellular peroxynitrite with high selectivity and sensitivity. 3a was successfully applied in the bioimaging of exogenous and endogenous peroxynitrite in living cells. The up-regulation of peroxynitrite in cancer cells and normal cells during 5-fluorouracil treatment was finally monitored.

Endoplasmic reticulum targeted fluorescent probe for the detection of hydrogen sulfide based on a twist-blockage strategy.

Hydrogen sulfide (H2S) is very important for humans and is involved in many physiological processes. Here, we designed and reported a new naked-eye colorimetric fluorescent probe Z1 for detecting H2S in absolute HEPES solution. The fluorescence intensity, after the reaction of the probe and H2S, is about 32 times that of the probe alone. When the concentration of H2S is 0-100 µM, the detection limit (DL) is rather low at about 0.15 µM (3σ/slope). The response mechanism is based on the leaving of the 2,4-dinitrobenzene moiety, followed by intramolecular cyclization to give a fluorescent iminocoumarin-benzothiazole group. Moreover, Z1 was applied to endogenous and exogenous H2S imaging in living cells. The high overlap coefficient proved that probe Z1 has good ER-tracker localization in living cells.

Reductive stress imaging in the endoplasmic reticulum by using living cells and zebrafish.

Excessive accumulation of reducing agents in the ER leads to a constitutively high UPR. And the co-function of GSH, Cys and HOCl in biological processes is not well understood. To address this, a TP probe, NPCC, was developed for monitoring reductive stress in the ER. It can also distinguish cancer cells from normal cells.