Young Tae Jang

Principle has it that even the most advanced super-resolution microscope would be futile in providing biological insight into subcellular matrices without well-designed fluorescent tags/probes. Developments in biology have increasingly been boosted by advances of chemistry, with one prominent example being small-molecule fluorescent probes that not only allow cellular-level imaging, but also subcellular imaging. A majority, if not all, of the chemical/biological events take place inside cellular

Hypochlorous acid (HOCl), as a highly potent oxidant, is well-known as a key "killer" for pathogens in the innate immune system. Recently, mounting evidence indicates that intracellular HOCl plays additional important roles in regulating inflammation and cellular apoptosis. However, the organelle(s) involved in the distribution of HOCl remain unknown, causing difficulty to fully exploit its biological functions in cellular signaling pathways and various diseases. One of the main reasons lies in

Of good report: Synthesis and screening of an 80-member tricarbocyanine library identified CyNAMLA-381 as a near-IR surface-enhanced Raman spectroscopy (SERS) reporter with good signal stability and higher sensitivity than the standard. Encapsulation of CyNAMLA-381 on gold nanoparticles and conjugation to an antibody afforded SERS nanotags with excellent sensitivity, stability, and tumor specificity in xenograft models (see picture).

Development of highly sensitive and selective sensing systems of divalent zinc ion (Zn(2+)) in organisms has been a growing interest in the past decades owing to its pivotal role in cellular metabolism, apoptosis, and neurotransmission. Herein, we report the rational design and synthesis of a Zn(2+) fluorescent-based probe by assembling lanthanide-doped upconversion nanoparticles (UCNPs) with chromophores. Specifically, upconversion luminescence (UCL) can be effectively quenched by the chromopho

The first BODIPY library (BD) was synthesized, and a highly selective glucagon sensor, Glucagon Yellow (BD-105), was discovered by fluorescence image-based screening method. BD library was synthesized via a Knoevenagel-type condensation reaction with 160 benzaldehydes and the 1,3 dimethyl-BODIPY scaffold. Using BD compounds, a fluorescence image-based screening was performed against three cell lines including AlphaTC1 and BetaTC6 cells which secret glucagon and insulin, respectively, and HeLa as

The need for detecting and labelling environmentally and biologically important analytes has driven considerable research efforts in developing fluorescent probes. During the sensing process, molecular motions (i.e., molecular rotations or vibrations) of a flexible fluorescent probe can be significantly altered by its embedding micro-environment or analyte, thereby leading to substantial changes in readout signals. Motion-induced change in emission (MICE) can be utilized as an effective sensing

Adenosine triphosphate (ATP), commonly produced in mitochondria, is required by almost all the living organisms; thus fluorescent probes for monitoring mitochondrial ATP levels fluctuation are essential and highly desired. Herein, we report a multisite-binding switchable fluorescent probe, ATP-Red 1, which selectively and rapidly responds to intracellular concentrations of ATP. Live-cell imaging indicated that ATP-Red 1 mainly localized to mitochondria with good biocompatibility and membrane pen

Abstract Drug toxicity is a long‐standing concern of modern medicine. A typical anti‐pain/fever drug paracetamol often causes hepatotoxicity due to peroxynitrite ONOO − . Conventional blood tests fail to offer real‐time unambiguous visualization of such hepatotoxicity in vivo. Here we report a luminescent approach to evaluate acute hepatotoxicity in vivo by chromophore‐conjugated upconversion nanoparticles. Upon injection, these nanoprobes mainly accumulate in the liver and the luminescence of n

Aggregation of amyloid β-peptide (Aβ) is implicated in the pathology of Alzheimer's disease (AD), with the soluble, Aβ oligomeric species thought to be the critical pathological species. Identification and characterization of intermediate species formed during the aggregation process is crucial to the understanding of the mechanisms by which oligomeric species mediate neuronal toxicity and following disease progression. Probing these species proved to be extremely challenging, as evident by the

Intracellular thermometry at the microscopic level is currently a hot topic. Herein we describe a small molecule fluorescent thermometer targeting mitochondria (Mito thermo yellow). Mito thermo yellow successfully demonstrates the ability to monitor the intracellular temperature gradient, generated by exogenous heating, in various cells.

Photoinduced electron transfer (PET) is one of the most important mechanisms for developing fluorescent probes and biosensors. Quantitative prediction of the quantum yields of these probes and sensors is crucial to accelerate the rational development of novel PET-based functional materials. Herein, we developed a general descriptor (Δ<i>E</i>) for predicting the quantum yield of PET probes, with a threshold value of ∼0.6 eV. When Δ<i>E</i> < ∼0.6 eV, the quantum yield is low (mostly <2%) due to

With the emerging interest in optical in vivo imaging, there is an increasing demand of photostable near-infrared (NIR) dyes. Herein we report the rational design of an amine tricarbocyanine structure with improved photostability (CyNA) and its combinatorial derivatization to render CyNA-414 as a NIR-fluorescent dye with stronger emission intensity and higher photostability than the NIR standard IndoCyanine Green (ICG).