BODIPY dyes and their derivatives: syntheses and spectroscopic properties.

The world of organic luminophores has been confined for a long time to fairly standard biological labeling applications and to certain analytical tests. Recently, however, the field has undergone a major change of direction, driven by the dual needs to develop novel organic electronic materials and to fuel the rapidly emerging nanotechnologies. Among the many diverse fluorescent molecules, the Bodipy family, first developed as luminescent tags and laser dyes, has become a cornerstone for these new applications. The near future looks extremely bright for "porphyrin's little sister".

The Chemistry of Fluorescent Bodipy Dyes: Versatility Unsurpassed

http://pubs.acs.org/doi/pdf/10.1021/cr400546e

Fluorescent Sensors for Measuring Metal Ions in Living Systems

This critical review covers the advances made using the 4-bora-3a,4a-diaza-s-indacene (BODIPY) scaffold as a fluorophore in the design, synthesis and application of fluorescent indicators for pH, metal ions, anions, biomolecules, reactive oxygen species, reactive nitrogen species, redox potential, chemical reactions and various physical phenomena. The sections of the review describing the criteria for rational design of fluorescent indicators and the mathematical expressions for analyzing spectrophotometric and fluorometric titrations are applicable to all fluorescent probes (206 references).

Fluorescent indicators based on BODIPY

The brain is a singular organ of unique biological complexity that serves as the command center for cognitive and motor function. As such, this specialized system also possesses a unique chemical composition and reactivity at the molecular level. In this regard, two vital distinguishing features of the brain are its requirements for the highest concentrations of metal ions in the body and the highest per-weight consumption of body oxygen. In humans, the brain accounts for only 2% of total body mass but consumes 20% of the oxygen that is taken in through respiration. As a consequence of high oxygen demand and cell complexity, distinctly high metal levels pervade all regions of the brain and central nervous system. Structural roles for metal ions in the brain and the body include the stabilization of biomolecules in static (e.g., Mg2+ for nucleic acid folds, Zn2+ in zinc-finger transcription factors) or dynamic (e.g., Na+ and K+ in ion channels, Ca2+ in neuronal cell signaling) modes, and catalytic roles for brain metal ions are also numerous and often of special demand.

Metals in Neurobiology: Probing Their Chemistry and Biology with Molecular Imaging

New heptamethine cyanine dyes with an alkylamino group at the central position were found to exhibit a large Stokes shift (>140 nm) and strong fluorescence. They were suggested to be a new paradigm for excited-state intramolecular charge transfer (ICT). The configuration change of the bridgehead amine accompanying ICT was investigated in different viscosity and pH media.

Heptamethine cyanine dyes with a large stokes shift and strong fluorescence: a paradigm for excited-state intramolecular charge transfer.

A simple PET fluorescence sensor (BDA) for Zn2+ that utilizes 1,3,5,7-tetramethyl-boron dipyrromethene as a reporting group and di(2-picolyl)amine as a chelator for Zn2+ has been synthesized and characterized. BDA has an excitation (491 nm) and emission wavelength (509 nm) in the visible range. The fluorescence quantum yields of the zinc-free and zinc-bound states of BDA are 0.077 and 0.857, respectively. With a low pKa of 2.1 ± 0.1, BDA has the advantage of less sensitivity to pH than fluorescein-based Zn2+ sensors, and the fluorescence emission of zinc-binding is pH-independent in the range of pH 3–10. Under physiological conditions, metal ions such as Na+, K+, Ca2+, Mg2+, Mn2+ and Fe2+ have little interference. The apparent dissociation constant (Kd) is 1.0 ± 0.1 nM. Using fluorescence microscopy, the sensor is shown to be capable of imaging intracellular Zn2+ changes.

Yunling Gao

Papers

Heptamethine cyanine dyes with a large stokes shift and strong fluorescence: a paradigm for excited-state intramolecular charge transfer.

Boron dipyrromethene fluorophore based fluorescence sensor for the selective imaging of Zn(II) in living cells

Synthesis and spectral properties of new boron dipyrromethene dyes

Fabrication of superhydrophobic copper meshes via simply soaking for oil/water separation

Preparation and properties of a silver particle-coated and 1-dodecanethiol-modified superhydrophobic melamine sponge for oil/water separation