Beibei Deng

A fast responsive two-photon fluorescent probe for imaging H2O2 in lysosomes with a large turn-on fluorescence signal

Hydrogen peroxide (H2O2) plays a crucial role in many biological processes in the human body. As our understanding of the complexity of physiological H2O2 in lysosome, investigative tools are required to make sense of this interconnectivity. Toward this goal, we have developed a new example of a fast responsive and lysosome-targeted two-photon H2O2 fluorescent probe (Lyso-HP) with a large turn-on fluorescence signal (80-fold fluorescence enhancement). The addition of H2O2 to Lyso-HP results a dramatic fluorescence enhancement around 550 nm. The probe could image exogenous and endogenous H2O2 in living cells and the probe was located in lysosomes with high colocalization coefficient (0.96) compared with LysoTracker. The large fluorescence enhancement of the two-photon probe Lyso-HP renders it attractive for imaging H2O2 in living tissues with deep tissue penetration. Significantly, the probe is feasible for fluorescently monitoring H2O2 level changes in lysosomes and suitable for fluorescence imaging of H2O2 in living tissues with deep penetration by using two-photon microscopy.

A dual-emission fluorescence-enhanced probe for imaging copper(II) ions in lysosomes

We have developed the first example of a fluorescence-enhanced and lysosome-targeted Cu2+ probe (Lys-Cu) with unique dual-channel emissions. The newly synthesized fluorescent probe Lys-Cu, which contains two recognition sites with different sensing mechanisms for Cu2+, displays fluorescence-enhanced dual-channel emissions with fluorescence response to Cu2+ in the lysosome pH environment. Fluorescence imaging shows that Lys-Cu is membrane-permeable and suitable for visualization of Cu2+ in lysosomes of living cells by dual-channel imaging.

A lysosome-targeted and ratiometric fluorescent probe for imaging exogenous and endogenous hypochlorous acid in living cells

Hypochorous acid plays important roles in numerous physiological and pathological processes. At the cell organelle level, an abnormal concentration of hypochorous acid in the lysosomes causes redox imbalance and the loss of function of the lysosomes. Herein, the first small molecule based, lysosomal-targeted ratiometric fluorescent HOCl probe (Lyso-HA) was synthesized through a rational design. The new probe was highly selective toward HOCl over other reactive oxygen species and exhibits a large variation (up to 97-fold) in its fluorescence ratio (I585/I450), with good signal resolution. The probe Lyso-HA is membrane-permeable and is suitable for ratiometric visualization of exogenous and endogenous HOCl at lysosomes in living cells.

Single Fluorescent Probe for Dual-Imaging Viscosity and H2O2 in Mitochondria with Different Fluorescence Signals in Living Cells

Mitochondria, as essential and interesting organelles within the eukaryotic cells, play key roles in a variety of pathologies, and its abnormalities are closely associated with Alzheimers disease (AD) and other diseases. Studies have shown that the abnormal of viscosity and concentration of hydrogen peroxide in mitochondria were all associated with AD. Accordingly, the detection of viscosity and hydrogen peroxide in mitochondria has attracted great attention. However, it remains a great challenge to explore a single probe, which can dual-detect the viscosity and H2O2 in mitochondria. Herein, in two ways to prevent the twisted internal charge transfer (TICT) process, we designed and sythesized the first dual-detection fluorescent probe Mito-VH that can visualize viscosity and H2O2 in mitochondria with different fluorescence signals in living cells.

A fluorescent probe for ratiometric imaging of exogenous and intracellular formed hypochlorous acid in lysosomes

We have developed a new lysosome-targeting ratiometric fluorescent probe (FL-HA) for specific determination of HOCl in living cells. The developed probe exhibits accurate lysosome-targeting ability, good signal resolution, and high selectivity. Moreover, fluorescence imaging shows that FL-HA could be used as a probe for ratiometric visualization of exogenous and endogenous HOCl in lysosomes with a high colocalization coefficient compared with a commercial lysosomal location dye.

A targetable fluorescent probe for imaging exogenous and intracellularly formed nitroxyl in mitochondria in living cells

Nitroxyl plays crucial roles in many biological pathways and can serve as a potent therapeutic agent for the treatment of heart failure. Recent studies suggest that HNO may be produced in mitochondria and the HNO formed might have functional consequences for mitochondrial activity. However, in order to study the function of HNO in mitochondria, a suitable research method is needed. Herein, through rational design, we synthesized a new mitochondria-targeted fluorescent nitroxyl probe (Mito-HNO). The developed probe was highly selective toward HNO over other reactive nitrogen species and reducing species. In addition, the probe Mito-HNO was rapidly responsive and suitable for visualization of HNO in mitochondria in living cells. The probe is expected to be employed in further revealing the biological function of HNO in subcellular mitochondria.

An ESIPT based fluorescent probe for imaging hydrogen sulfide with a large turn-on fluorescence signal

Through an intramolecular nucleophilic substitution reaction and ESIPT mechanism, we designed and synthesized a fluorescent hydrogen sulfide probe with a large turn on fluorescence signal (400-fold). The new probe exhibits high selectivity, good membrane-permeability and is suitable for the visualization of exogenous and endogenous hydrogen sulfide in living cells.

Development of a viscosity sensitive fluorescent probe for real-time monitoring of mitochondria viscosity

Using hemicyanine and carbazole as an acceptor and a donor, respectively, we designed and synthesized two new mitochondrial-targeted fluorescent viscosity probes (MHC-V1 and MHC-V2). The new probes were membrane-permeable and suitable for visualization of the changes of viscosity within the mitochondria of living cells.

Preparation of a Two-Photon Fluorescent Probe for Imaging H 2 O 2 in Lysosomes in Living Cells and Tissues

Hydrogen peroxide (H2O2) plays important roles in many physiological and pathological processes. At the cellular organelle level, the abnormal concentrations of H2O2 in the lysosomes may cause redox imbalance and the loss of the critical functions of the lysosomes. Herein, we describe the preparation of a potent lysosome-targeted two-photon fluorescent probe (Lyso-HP) for the detection of H2O2 in the lysosomes in the living cells. This unique fluorescent probe can also be employed to effectively detect H2O2 in the living tissues using two-photon fluorescence microscopy.