The effect of deuterium on the photophysical properties of DNA-stabilized silver nanoclusters

Abstract

We investigated the effect of using D₂O <i>versus</i> H₂O as solvent on the spectroscopic properties of two NIR emissive DNA-stabilized silver nanoclusters (DNA-AgNCs). The two DNA-AgNCs were chosen because they emit in the same energy range as the third overtone of the O-H stretch. Opposite effects on the ns-lived decay were observed for the two DNA-AgNCs. Surprisingly, for one DNA-AgNC, D₂O shortened the ns decay time and enhanced the amount of μs-lived emission. We hypothesize that the observed effects originate from the differences in the hydrogen bonding strength and vibrational frequencies in the two diverse solvents. For the other DNA-AgNC, D₂O lengthened the ns decay time and made the fluorescence quantum yield approach unity at 5 °C.