Light-triggered modulation of cellular electrical activity by ruthenium diimine nanoswitches.

摘要: Ruthenium diimine complexes have previously been used to facilitate light-activated electron transfer in the study of redox metalloproteins. Excitation at 488 nm leads a photoexcited state, which complex can either accept or donate an electron, respectively, presence soluble sacrificial reductant oxidant. Here, we describe novel application these mediating light-induced changes cellular electrical activity. We demonstrate that RubpyC17 ([Ru(bpy)_(2)(bpy-C17)]^(2+), where bpy is 2,2′-bipyridine and bpy-C17 2,2′-4-heptadecyl-4′-methyl-bipyridine), readily incorporates into plasma membrane cells, as evidenced by membrane-confined luminescence. Excitable cells incubated then illuminated ascorbate undergo depolarization leading firing action potentials. In contrast, same experiment performed with oxidant ferricyanide, instead ascorbate, hyperpolarization. These experiments suggest illumination membrane-associated alters cell potential increasing negative charge on outer face capacitor, effectively depolarizing membrane. rule out two alternative explanations for changes, using patch clamp experiments: (1) direct interaction ion channels (2) perforation. show incorporation neuroendocrine enables secretion monitored amperometry. While present work focused ruthenium complexes, findings point more generally broader other transition metal mediate biological changes.