The dual pH‐induced reversible self‐assembly (PIRSA) of Au‐nanoparticles (Au NPs) is reported, based on their decoration with the self‐complementary guanidiniocarbonyl pyrrole carboxylate zwitterion (GCPZ). The assembly of such functionalized Au NPs is found at neutral pH, based on supramolecular pairing of the GCPZ groups. The resulting self‐assembled system can be switched back to the disassembled state by addition of base or acid. Two predominant effects that contribute to the dual‐PIRSA of Au NPs are identified, namely the ionic hydrogen bonding between the GCPZ groups, but also a strong hydrophobic effect. The contribution of each interaction is depending on the concentration of GCPZ on NPs, which allows to control the self‐assembly state over a wide range of different water/solvent ratios.

Small peptides capable of assembling into well-defined nanostructures have attracted extensive attention due to their interesting applications as biomaterials. This work reports the first example of a pillararene functionalized with a guanidiniocarbonyl pyrrole (GCP)-conjugated short peptide segment. The obtained amphiphilic peptide 1 spontaneously self-assembles into a supramolecular β-sheet in aqueous solution based on host-guest interaction between pillararene and GCP unit as well as hydrogen-bonding between the peptide strands. Interestingly, peptide 1 at low concentration shows transitions from small particles to "pearl necklace" assemblies, and finally to branched fibers in a time-dependent process. At higher concentration, it directly assembles into twisted β-sheet tapes. Notably, without pillararene moiety, the control peptide A forms α-helix structure with morphology changing from particles to bamboo-like assemblies depending on concentration, indicating a significant role of the pillararene-GCP host-guest interaction for the secondary structure formation. Moreover, peptide 1 can serve as an efficient gene transfection vector.

We report a pH‐ and temperature‐controlled reversible self‐assembly of Au‐nanoparticles (AuNPs) in water, based on their surface modification with cationic guanidiniocarbonyl pyrrole (GCP) and zwitterionic guanidiniocarbonyl pyrrole carboxylate (GCPZ) binding motifs. When both binding motifs are installed in a carefully balanced ratio, the resulting functionalized AuNPs self‐assemble at pH 1, pH 7 and pH 13, whereas they disassemble at pH 3 and pH 11. Further disassembly can be achieved at elevated temperatures at pH 1 and pH 13. Thus, we were able to prepare functionalized nanoparticles that can be assembled/disassembled in seven alternating regimes, simply controlled by pH and temperature.

A dual pH-responsive two component hydrogelator with aggregation-induced emission properties is described. The orchestration of supramolecular guadiniumcarbonylpyrrole dimerisation and the recognition of carboxylic acid is reason for the gelation.

Herein, we describe the development of a modular approach to create pH responsive polymeric nanoparticles. We combined monomers containing guadiniocarbonyl pyrrole carboxylate zwitterion (GCP)-zwitterion with different simple monomers by ring-opening metathesis polymerization (ROMP). The dimerization of the GCP-zwitterion allows formation of polymer nanoparticles in neutral and acidic aqueous solution, which can reversibly be rearranged by changing the pH. The modularity of our approach allowed us to tune the solubility of the polymeric nanoparticles and preserve the pH switchability of the systems. We were able to use the pH switchability for reversible uptake and partial release of Nile red.