BODIPY dyes modification

BODIPY is a short for 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene, the basic structure of this type of fluorophore (see Fig. 6.5). Derivatives of this dye have been created by modification of positions 1, 3, 5, 7, and 8, generating an array of fluorophores with very distinct excitation and emission properties [38]. Molecular Probes has synthesized a wide number of BODIPY dyes whose excitation... 

The building block of BODIPY can be well tailored by structural modification, enriching the family of BODIPY dyes. Indeed, the BODIPY scaffold serves as a promising platform for the construction of molecular sensors. Given that BODIPY derivatives bear excellent characteristics, such as intense fluorescence quantum yields, sharp absorption and fluorescence emission spectra, a tremendous expansion has been witnessed in BODIPY-based probes for versatile applications. The established BODIPY-based probes always exhibit fluorescence turn-on or ratiometric responses to a target, by making full use of photophysical processes with common channels such as PET, ICT or FRET. There is no doubt that the rational construction of BODIPYs with these photophysical features still serves as effective strategies to further develop powerful probes or chemodosimeters. 

BODIPY dyes were subjected to modifications in their meso position as the previous fluorescein dyes. Aromatic moieties at this position are perpendicular to the molecular plane but, nevertheless, affect the fluorescence properties of the core [99]. Subtle manipulation of the redox potential can be also read out by changes of the fluorescence lifetime as exemplified in a substrate for phosphoester cleavage [100]. Depending on of the redox properties of the substituents, fluorescence can be turned on and off [101]. When the electrochemical potential of the substituent is altered during a reaction, a fluorogenic probe for this particular reaction is tailored. This was exploited for studying interfacial electron transfer [61]. More applications appear feasible. 

Boradiazaindacene (BODlPY)-based fluorescence probes have been used for detecting Cd " in cells (Figure 3). The optical properties of BODIPY can be tuned by chemical modifications on the dye core. BODIPY dyes undergo an ICT process with a functional group at the 3 -position whereas the substituents at the meso position can alter the efficiency of the PET process [58]. 

A BODIPY dye has been synthesised as a phosphoramidite for incorporation onto oligonucleotides during chemical synthesis or attached to C5 of dU. A cationic dye (83) based on -methylstilbazole attached to threoninol has been described, that causes DNA to form interstrand clusters when three such modifications are attached to the end of DNA. ° Fluorescently-labelled DNA will also form clusters around a positively-charged perylene molecule, the latter acting as a superquencher of fluorescence. The tetrameric 1,8-naphthyridine (84) has been shown to intercalate into two hairpin loops forming a loop-loop kissing complex. ... 

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