Orthogonal Self-Assembly of Cyclodextrin-Decorated Noble Metal Nanoparticles via Photoresponsive Molecular Recognition in Aqueous Solution

Abstract

Control over the self-assembly of mixed nanoparticles (NP) is a challenging but versatile concept for the bottom-up fabrication of novel nanomaterials. Moreover, stimulus-responsive self-assembly is fundamental to the development of adaptive and intelligent materials. In this study, we demonstrate the orthogonal self-assembly of cyclodextrin (CD) decorated noble metal NP. Utilizing the guest selectivity of αCD and γCD, divalent photoresponsive supramolecular crosslinkers were identified and applied in selective NP assembly. By design of specific crosslinkers, narcissistic as well as social self-sorting of sub 10 nm metal NP was enabled. Irradiation experiments confirmed that the aggregation process is induced by photoresponsive host-guest chemistry, which allows to form and dissolve the NP aggregates over several cycles and to photo-initiate the NP aggregation. The molecular recognition as well as the specific response of CD-functionalized NP show significant potential in the reversible self-assembly of inorganic-organic hybrid nanomaterials in aqueous solution.