Abstract
The kinetic rate equation for the photosensitized cleavage reaction of surface-bound photolabile chromophores with free diffusion of sensitizer molecules from the bulk of a solution to the surface is derived by determining the stationary solution of a diffusion equation with suitable boundary conditions. The relation between the phenomenological rate constant for the photosensitized reaction at the surface and in the bulk is established. Applying the result to the analysis of an experimental example, the origin of the quasi zeroth-order kinetics of the sensitized reaction is revealed. A theoretical comparison of intramolecular sensitization in photocleavable protecting groups with a molecular antenna and sensitization with the freely diffusing sensitizer shows that in a typical case sensitization with free diffusion is more effective than intramolecular sensitization for sensitizer concentrations higher than 5 mM.
Similar content being viewed by others
Notes and references
M. C. Pirrung, How to make a DNA chip, Angew. Chem., Int. Ed., 2002, 41, 1276–1289.
R. J. Lipshutz, S. P. A. Fodor, T. R. Gingeras and D. J. Lockhart, High density synthetic oligonucleotide arrays, Nat. Genet., 1999, 21, 20–24.
S. P. A. Fodor, J. L. Read, M. C. Pirrung, L. Stryer, A. T. Lu and D. Solas, Light-directed, spatially addressable parallel chemical synthesis, Science, 1991, 251, 767–773.
P. Stegmaier, J. M. Alonso and A. del Campo, Photoresponsive surfaces with two independent wavelength-selective functional levels, Langmuir, 2008, 24, 11872–11879.
G. Mayer and A. Heckel, Biologically active molecules with a “light switch”, Angew. Chem., Int. Ed., 2006, 45, 4900–4921.
A. del Campo, D. Boos, H. W. Spiess and U. Jonas, Surface modification with orthogonal photosensitive silanes for sequential chemical lithography and site-selective particle deposition, Angew. Chem., Int. Ed., 2005, 44, 4707–4712.
C. G. Bochet, Photolabile protecting groups and linkers, J. Chem. Soc., Perkin Trans. 1, 2002, 125–142.
V. San Miguel, C. G. Bochet and A. del Campo, Wavelength-selective caged surfaces: how many functional levels are possible?, J. Am. Chem. Soc., 2011, 133, 5380–5388.
M. C. Pirrung and V. S. Rana, Photoremovable Protecting Groups in DNA Synthesis and Microarray Fabrication, in Dynamic Studies in Biology: Phototriggers, Photoswitches, and Caged Compounds, ed. R. S. Givens and M. Goeldner, J. Wiley & Sons, New York, 2005, p. 341.
A. P. Pelliccioli and J. Wirz, Photoremovable protecting groups: reaction mechanisms and applications, Photochem. Photobiol. Sci., 2002, 1, 441–458.
A. Hasan, K. P. Stengele, H. Giegrich, P. Cornwell, K. R. Isham, R. A. Sachleben, W. Pfleiderer and R. S. Foote, Photolabile protecting groups for nucleosides: Synthesis and photodeprotection rates, Tetrahedron, 1997, 53, 4247–4264.
S. Walbert, W. Pfleiderer and U. E. Steiner, Photolabile protecting groups for nucleosides: Mechanistic studies of the 2-(2-nitrophenyl)ethyl group, Helv. Chim. Acta, 2001, 84, 1601–1611.
D. Wöll, S. Walbert, K.-P. Stengele, T. Albert, T. Richmond, J. Norton, M. Singer, R. Green, W. Pfleiderer and U. E. Steiner, Triplet-sensitized photodeprotection of oligonucleotides in solution and on microarray chips, Helv. Chim. Acta, 2004, 87, 28–45.
D. Wöll, J. Smirnova, W. Pfleiderer and U. E. Steiner, Highly efficient photolabile protecting groups with intramolecular energy transfer, Angew. Chem., Int. Ed., 2006, 45, 2975–2978.
D. Wöll, S. Laimgruber, M. Galetskaya, J. Smirnova, W. Pfleiderer, B. Heinz, P. Gilch and U. E. Steiner, On the mechanism of intramolecular sensitization of photocleavage of the 2-(2-nitrophenyl)propoxycarbonyl (NPPOC) protecting group, J. Am. Chem. Soc., 2007, 129, 12148–12158.
D. Wöll, J. Smirnova, M. Galetskaya, T. Prykota, J. Bühler, K. P. Stengele, W. Pfeiderer and U. E. Steiner, Intramolecular sensitization of photocleavage of the photolabile 2-(2-nitrophenyl)propoxycarbonyl (NPPOC) protecting proup: photoproducts and photokinetics of the pelease of pucleosides, Chem.–Eur. J., 2008, 14, 6490–6497.
S. F. Burlatsky, Kinetics of diffusion-controlled heterogeneous reactions in the case of small reagent concentrations, Dokl. Akad. Nauk SSSR, 1979, 247, 373–376.
N. L. Thompson, T. P. Burghardt and D. Axelrod, Measuring surface dynamics of biomolecules by total internal reflection fluorescence with photobleaching recovery or correlation spectroscopy, Biophys. J., 1981, 33, 435–454.
S. F. Burlatsky, O. F. Ivanov and J. M. Deutch, Influence of the spatial distribution of reactive centers on diffusion controlled reactions, J. Chem. Phys., 1992, 97, 156–161.
Burlatskii did not use the rate constant kσ but a quantity h that is related to our kσ by h = kσ/D.
F. C. Collins and G. E. Kimball, Diffusion-controlled reaction rates, J. Colloid Sci., 1949, 4, 425–437.
D. Kucina, PhD University of Konstanz, Konstanz, 2011.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Wöll, D., Lukzen, N. & Steiner, U.E. Diffusion-controlled sensitization of photocleavage reactions on surfaces. Photochem Photobiol Sci 11, 533–538 (2012). https://doi.org/10.1039/c1pp05319a
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1039/c1pp05319a