Novel photoactive self-assembled monolayer for immobilization and cleavage of DNA

This contribution reports on a novel self-assembled monolayer (SAM) on a gold surface, able to immobilize double-strand DNA and to induce its cleavage upon light excitation. DNA binding with the SAM is mainly driven by a highly favored electrostatic interaction, and it is shown that DNA immobilization takes place without impairing its intrinsic high order. SAM irradiation leads to an uncommon defluorination reaction, and it is unambiguously demonstrated that DNA breakage is strictly interrelated to this photochemical pathway. The photocleavage process is very efficient, is exclusively controlled by illumination conditions, seems to be non-base-specific, and does not require external additives. These features, together with the low excitation energy required, the prolonged thermal stability under physiological conditions, and the ease of preparation, make the SAM presented herein an appealing model system for designing nanodevices for applications where efficient, non-base-specific, and externally tunable cleavage of nanoscaled DNA arrays is required. RI Sortino, Salvatore/E-4684-2011