Isotopic Control over Self-Assembly in Supramolecular Gels

Area of Science:

• Supramolecular chemistry
• Materials science
• Biophysical chemistry

Background:

• Peptide-based gels are widely studied, often assuming no difference between H 2 O and D 2 O solvent systems.
• Understanding solvent effects is crucial for controlling self-assembled material properties.

Purpose of the Study:

• To investigate the impact of switching from H 2 O to D 2 O on low-molecular-weight dipeptide-based gels.
• To determine if isotopic composition influences gelation kinetics, self-assembled structures, and resulting gel properties.

Main Methods:

• Formation of dipeptide-based gels by decreasing pH in both H 2 O and D 2 O.
• Comparative analysis of gel structures and properties under different isotopic conditions.
• Examination of gelation kinetics and self-assembly behavior.

Main Results:

• In most cases, minimal structural differences were observed at high pH.
• Lowering the pH significantly affected gelation kinetics in D 2 O compared to H 2 O.
• Differences in self-assembled structures were observed in some cases, leading to altered gel properties.
• Isotopic effects were not universally observed but were significant when present.

Conclusions:

• The assumption of no isotopic effect when switching between H 2 O and D 2 O is not universally valid for peptide-based gels.
• Isotopic composition can be a critical factor influencing the self-assembly process and the final properties of peptide gels.
• This study demonstrates the possibility of achieving isotopic control over the properties of peptide-based gels.