Multiswitchable photoacid-hydroxyflavylium-polyelectrolyte nano-assemblies.

Alexander Zika,Franziska Gröhn

doi:10.3762/bjoc.17.17

Abstract

Light- and pH-responsive nano-assemblies with switchable size and structure are formed by the association of a photoacid, anthocyanidin, and a linear polyelectrolyte in aqueous solution. Specifically, anionic disulfonated naphthol derivatives, neutral hydroxyflavylium, and cationic poly(allylamine) are used as building blocks for the ternary electrostatic self-assembly, forming well-defined supramolecular assemblies with tunable sizes of 50 to 500 nm. Due to the network of possible chemical reactions for the anthocyanidin and the excited-state dissociation of the photoacid upon irradiation, different ways to alter the ternary system through external triggering are accessible. The structure and trigger effects can be controlled through the component ratios of the samples. Dynamic and static light scattering (DLS, SLS) and ζ-potential measurements were applied to study the size and the stability of the particles, and information on the molecular structure was gained by UV–vis spectroscopy. Isothermal titration calorimetry (ITC) provided information on the thermodynamics and interaction forces in the supramolecular assembly formation.

Highlights

Supramolecular nanoscale assemblies responding to multiple stimuli are highly desirable in various fields including transport systems, sensors, and optoelectronic applications [1,2,3,4,5,6,7,8]
It has been highly desirable to establish concepts that could be applied in aqueous solution, with the Schmuck binding motif – the guanidiniocarbonyl‐pyrrole zwitterion binding motif – representing a most versatile binding motif with potential from nanostructure design to biomedicine [22,23,24,25]
In conclusion we have developed a novel reversible multiswitchable system consisting of a cationic polyelectrolyte, a hydroxyflavylium molecule (Flavy), and a photoacid

Summary

Introduction

Supramolecular nanoscale assemblies responding to multiple stimuli are highly desirable in various fields including transport systems, sensors, and optoelectronic applications [1,2,3,4,5,6,7,8]. It has been highly desirable to establish concepts that could be applied in aqueous solution, with the Schmuck binding motif – the guanidiniocarbonyl‐pyrrole zwitterion binding motif – representing a most versatile binding motif with potential from nanostructure design to biomedicine [22,23,24,25]. We have built the nanoscale assemblies from polyelectrolytes and multiply oppositely charged molecules based on electrostatic interactions and secondary interactions such as Beilstein J.

Objectives

Results

Conclusion