Title
Tuning Chirality Transfer and Amplification of Supraparticles via Solvent Inducing Self-Aggregation of Chiral Gold Nanoclusters
Author
Zhongjie Ma, Guanbin Gao, Zhuoying Luo, Xintong Tang, Taolei Sun
Year
2019
Journal
The Journal of Physical Chemistry C
Abstract
The urgent need to understand the origin of chirality in a diverse scale has evoked a tremendous number of investigations for the control of metal nanoparticle self-aggregates and their tuning of supraparticle chirality. However, the tuning of transfer and amplification of supraparticle chirality in nanoparticle systems remains a challenge. Here we show an approach for tuning chirality transfer and amplification of supraparticles from chiral gold nanoclusters (AuNCs) through the introduction of solvents with different polarities and protonations. The degree of self-aggregation of AuNCs decorated with chiral ligands (N-isobutyryl-l(d)-cysteine, l(d)-NIBC) is strongly affected by solvent composition. In the pure or mixed solvents that contain a protic polar solvent (ethanol, methanol and water), chiral AuNCs prefer to self-aggregate into supraparticles with mirror optical activities, and the degree of AuNC self-aggregation is enhanced with an increase in the polarity of protic polar solvents, which produce greater chirality transfer and amplification of the supraparticles. While in the aprotic polar solvent (DMSO), chiral AuNCs cannot self-aggregate into supraparticles. Moreover, a possible mechanism is proposed based on the hydrogen bond formation between solvent molecules or between solvent and the surface ligands of AuNCs to explain the solvent-polarity-dependent self-aggregation of AuNCs. This study not only presents a promising method to easily tune the chirality transfer and amplification of supraparticles of nanoclusters, but also offers insight into better understanding the chiral origin of supraparticles of metal nanoparticles.
Instrument
J-1500
Keywords
Circular dichroism, Nanostructures, Chemical stability, Stereochemistry, Aggregation, Materials