Radiationless Transitions of G4 Wires and dGMP

Abstract

Steady-state and time-resolved emission techniques were employed to study the nonradiative process of deoxygunaosine monophosphate (dGMP) and novel uniform continuous G4 wires containing hundreds of stacked tetrads. We found that the time-resolved emissions of both dGMP and G4 wires decay nonexponentialy. At room temperature, the short-time decay of the G4 wires is about 10 ps. At low temperatures in ice, the fluorescence quantum yields of both dGMP and G4 wires increase as the temperature decreases. For the G4 wires, the fluorescence quantum yield increases from about 10−3 at room temperature to about 0.03 at liquid-nitrogen temperatures. The asymptotic long-time decay of the lifetime-corrected emission of the G4 wires obeys a power law. At all temperatures, the average fluorescence decay time of G4 wires is longer than that of dGMP. We successfully used an inhomogeneous nonradiative model to fit the experimental results.