nn0c06938_si_002.pdf (2.83 MB)
Download fileRedox-Driven In Situ Helix Reversal of Graphene-Based Hydrogels
journal contribution
posted on 17.11.2020, 22:31 authored by Yaqian Zhang, Minggao Qin, Chao Xing, Changli Zhao, Xiaoqiu Dou, Chuanliang FengControlling the handedness of dynamic
helical nanostructures of
supramolecular assemblies by external stimuli is of great fundamental
significance with appealing morphology-dependent applications. Significantly,
access to in situ chirality transformation of dynamic
multistimuli-responsive systems can provide channels for real-time
monitoring of the transfer processes in biological systems. However,
efforts to achieve helix inversion in an all-gel-state and to comprehend
the phenomena at a molecular scale are scarce. Herein, we introduce
an example of supramolecular hydrogel in which graphene oxide (GO)
incorporation leads to opposite helicity of the l-phenylalanine
derivative (LPFEG) upon UV irradiation. The gelator modulates different
degrees of packing that are responsible for the initial construction
of right-handed nanofibers in GO surfaces and for the change in helix
to preferred left-handedness in RGO surfaces caused by GO reduction.
Specifically, LPFEG shows a mixture of right- and left-handed nanofibers
with an appropriate exposure to UV light. A thermal-reversible transformation
of chirality is also discovered in the supramolecular assemblies,
allowing a dynamic and invertible flip of helicity upon heating and
cooling. The morphology transformation makes the hybrid an ideal candidate
for application in a precisely controlled drug delivery process. It
can unexpectedly serve as a photosensitizer and a carrier for enantioselective
absorption of specific chiral drugs enantiomer (l-dopa and S-naproxen sodium) and also exhibit on-demand drug release
due to the helix reversal induced by light irradiation. Our results
illustrate how the surface reactivity can direct the helical organization
of adsorbed fibers, which in turn provide control over enantioselective
absorption of chiral drug enantiomers, further giving rise to on-demand
drug release due to handedness inversion upon UV irradiation.
History
Usage metrics
Read the peer-reviewed publication
Categories
Keywords
helixtransformationexhibit on-demand drug releasesupramolecular assemblieshelicityinversionLPFEGRGOUV irradiationchiral drug enantiomersassemblyhelicalchiralitynanofiberhandedneschiral drugs enantiomerGraphene-Based Hydrogels ControllingSitu Helix Reversalsurfaceenantioselective absorptionapplicationon-demand drug releasedrug delivery process