Noble metal plasmonic nanostructure related chromisms

Chromism focuses on the phenomena of color change, and the studies in the related area have conventionally been centered on organic dyes. In recent decades, noble metal nanostructures, featured with rich optical properties arising from their characteristic localized surface plasmon resonances, have emerged as an alternative family of color-rendering agents, and have therefore been introducing new trends into the research realm of chromisms. Here in this review we summarize the related studies on noble metal plasmonic nanostructure related chromisms, which are sorted into four major categories, namely, solvatochromism, sorptiochromism, aggregachromism and chronochromism. For each category, the basic principles (some with comparison to those for dye-related systems) are delineated, followed with examples illustrating the performances and utilizations of representative systems. Of note, we put particular emphasis on the category of chronochromism, which, in our opinion, has not received as much deserved attention yet promises great potential in practical applications. In the final section, we discuss the challenges that plasmonic nanostructures are currently facing, and outlook the opportunities that may emerge in the near future.