Small nanoclusters of noble metals have emerged as promising fluorescent markers in nanomedicine applications, due to their high brightness, low toxicity and tunability. More recently, these materials have been implicated as having antimicrobial properties and can be targeted to multidrug resistant microbes. However, for silver nanoclusters (AgNCs), it is still problematic to delineate relative contributions of size, configuration, and environment on the optical properties, much less the antimicrobial mechanism.
We aim to combine theoretical and experimental studies to understand the structure-property relationship in these tuned systems. It is proposed herein to (1) tune the optical properties of AgNCs using a refined DNA scaffolding protocol; (2) characterize the AgNCs to confirm their tuned optical properties (3) calculate the effects of the tuning protocol in the quantum confined regime for comparison to, and prediction of, additional tunable analogues. The outcomes of this project will contribute to the fundamental knowledge of new fluorophores.
Relevance to the mission of the NIH In the last decade, silver nanoclusters (AgNCs) received attention as small, photostable, tunable, biocompatible fluorophores that offer optical advantages, compared to organic dyes or quantum dots. Two important potential applications of Agency are for biomedical imaging and combating antibiotic resistant microbes. Easily photobleached organic dyes are currently in use for assisting surgeons in cleaning out cancerous tissue, leaving the good tissue untouched. However, the patient prognosis would be greatly improved using a material like AgNCs with its longer fluorescent lifetimes. More recently, AgNCs were shown to have an added benefit as antimicrobials, targeting the public health topic that has received much discussion, the growing prevalence of ?superbugs?, antibiotic resistant microbes. With statistics of 23,000 succumbing to death of the 2 million people with multidrug resistant infections in 2013 alone, the problem is in national focus for which a solution can be sought by investigating the antimicrobial mechanisms of AgNCs.
