Maleimide-Modified Gold Nanoparticles (AuNPs): A Versatile Platform for Interfacial Click Reactions Leading to Chemically Modified AuNPs

The maleimide moiety can undergo a wide variety of organic reactions, including Diels-Alder reactions, dipolar cycloadditions, and Michael-type additions, making it a suitable moiety for further elaboration of the functionality at the interface of gold nanoparticles (AuNPs) through key reactions that are useful in a host of applications. This account will cover: (1) our approach to prepare maleimide-AuNPs, (2) our survey of the scope of the reactivity of organic-solvent-soluble maleimide-AuNPs, which are very slow, impractical, and required the development of high-pressure techniques in AuNP chemistry yielding dramatic results, and (3) the extension of these ideas to prepare water-soluble small AuNPs to expand the scope of the organic transformation to aqueous environments. Within each of these sections there were challenges that had to be overcome, and we will describe the evolution of the ideas so that readers can get a glimpse of our thinking and problem solving as we proceeded. 1 Introduction 2 Maleimide-AuNPs: The Synthetic Strategy 3 Reactivity of the Organic-Solvent-Soluble Maleimide-AuNP Template 4 Synthesis of the Water-Soluble Maleimide-AuNP Template 5 Reactivity of the Water-Soluble Maleimide-AuNP Template 6 Concluding Remarks