How Water Regulates Nonradiative Deactivation of DNA-Templated Green-Yellow Rod-Shaped Silver Clusters

Area of Science:

• Biophysical Chemistry
• Nanotechnology
• Molecular Imaging

Background:

• DNA-stabilized silver clusters are promising fluorophores for bioimaging.
• Optimizing their fluorescence efficiency is crucial for developing advanced imaging probes.
• Nonradiative deactivation pathways significantly limit fluorescence quantum yield.

Purpose of the Study:

• To theoretically investigate structural factors influencing the fluorescence efficiency of DNA-stabilized silver clusters.
• To understand the mechanisms of nonradiative deactivation in green-yellow emitting silver clusters.
• To identify design strategies for enhancing the fluorescence quantum yield.

Main Methods:

• Theoretical examination of five oligonucleotide-stabilized rod-shaped silver clusters.
• Computational analysis of structural features affecting fluorescence.
• Modeling of internal conversion and intersystem crossing rates.

Main Results:

• Reducing water molecule interaction with silver clusters decreases internal conversion.
• Increased water interaction accelerates internal conversion to the ground state.
• Guanine content modulation alters energy gaps, influencing intersystem crossing quenching when water contact is limited.

Conclusions:

• Minimizing water-silver cluster interaction is key to enhancing fluorescence.
• Strategic adjustment of guanine content can further modulate fluorescence through intersystem crossing.
• These findings provide rational design principles for improving DNA-silver cluster fluorophores.