Fluorophores catalytic production

Fig. 22 (a) Oxymercuration reaction for Hg2+ sensing with 58. (b) Oxidation state-selective Pd/Pt catalytic production of fluorophores 61 and 62 from 60. Nonfluorescent 58 is selectively converted into strongly green fluorescent 59 and nonfluorescent 60 is either converted into strongly green fluorescent 61 or strongly greenish-yellow fluorescent 62... 

Reaction-based indicators which are catalytically transformed by the analyte of interest are an attractive alternative due to the simple reason mentioned in the context of enzymes at the beginning of Sect. 4 one analyte molecule is qualified to produce a lot of fluorophores, increasing sensitivity dramatically. For an actual quantitative determination, however, the same conditional constraints are relevant like in enzyme-based methods, i.e., reproducible and defined incubation times, temperature, pH, etc. Up to now, transition metal cations have been mostly shown to be detectable by catalytic fluorophore production. 

Another approach to the observation of catalytic events by SMFS is the use of fluorophore-labeled substrates that change fluorescence intensity upon conversion to products. This type of substrates has previously been applied to the monitoring of enzymatic catalysis. In the context of Cu(If)-triggered catalysis, we have developed the fluorophore-labeled substrates shown in Figure 3.5. 

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