Great efforts have been devoted over the past decade toward developing chemoselective probes for imaging that rely on the induction/enhancement of fluorescence upon activation of an otherwise dimly emissive fluorophore via reaction with a molecular entity.1 Some of these fluorogenic probes exploit bond cleavage and removal of an intramolecular quenching moiety. Others rely on a change in the electronic structure of the chromophore, or on the deactivation of an intramolecular quenching pathway (e.g. photoinduced electron transfer PET2 or free rotation3) upon reaction with an analyte of interest. The new probes have found applications in bioimaging, imaging of catalytic reactions, and in high throughput screening, to name a few examples. In this presentation we will describe our progress on the preparation of various types of two-segment trap-reporter redox sensitive fluorogenic probes. We will discuss their mechanism of action providing a rationale for the choices of trap and reporter segments.4 We will demonstrate the use of the probes in analytical assays and in state-of-the-art single molecule fluorescence studies5 exploring redox reactions on electrode surfaces, highlighting the potential for the new probes to study catalytic redox reactions. We will close the presentation by extending the paradigm of activatable probes beyond fluorescence, showing that other photophysical or photochemical properties may be activated following a reaction of interest. In particular, we will show how singlet oxygen photosensitization may be activated following an oxidation reaction at the trap segment of a photosensitizer in what constitutes an autocatalytic activation of 1O2 sensitization.6 References (1) Chan, J.; Dodani, S. C.; Chang, C. J. Nat Chem 2012, 4, 973-984; (2) de Silva, A. P.; Gunaratne, H. Q. N.; Gunnlaugsson, T.; Huxley, A. J. M.; McCoy, C. P.; Rademacher, J. T.; Rice, T. E. Chem. Rev. 1997, 97, 1515-1566. (3) Turro, N. J.; Ramamurthy, V.; Scaiano, J. C.; University Science Books: Sausalito, CA, 2009. (4) a) Krumova, K.; Cosa, G.; J. Am. Chem. Soc., 2010, 132, 17560. b) Krumova, K.; Friedland, S.; Cosa, G.; J. Am. Chem. Soc., 2012, 134, 10102. c) Krumova, K.; Greene, L.; Cosa, G.; J. Am. Chem. Soc., 2013, 135 17135. (5) Godin, R.; Cosa, G.; Submitted. (6) Durantini, A.; Greene, L., E.; Lincoln, R.; Cosa, G.; Submitted

From chemoselective fluorescence imaging to autocatalytic singlet oxygen generation enabled by activatable probes

251st National Meeting (2016)

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