Abstract

Metal nanoclusters have been the subject of much interest due to their striking chemical and optical features, including strong absorption and intense luminescence. A variety of applications have been proposed for nanoclusters from biological labeling, to sensing and imaging [1]. Generation and stabilization of metal nanoclusters are major issues, for which a wealth of ways have been proposed to synthesize and stabilize these species. One common approach is reliant on the reduction of the metal ions, using chemical and optical means, in the presence of suitable stabilizing scaffolds, such as polymers and proteins. In addition, direct laser writing has been used to efficiently form and stabilize silver nanoclusters in solid-state matrices, such as glass [2], zeolite [3], and polymer [4], enabling compelling applications such as optical data storage and micro-labeling. Although gold is widely considered as being less toxic, and highly photo-stable among other noble metals [1], direct laser writing has been limited to silver, and micro-patterning of gold nanoclusters remains elusive. In this work, we show that polymer- scaffolded gold nanoclusters can be generated using sub-microwatt laser beam, allowing micro-patterning with a cost-effective and facile technique.

© 2019 IEEE