Probing the self-assembled structures and pKa of hydrogels using electrochemical methods

Abstract

The surface chemistry of the aggregated structures that form the scaffold in self-assembled hydrogels – their charge, hydrophobicity and ion-binding dynamics – plays an important role in determining the gel properties and the gel's suitability for specific applications. However, there are limited methods available for the study of this surface chemistry. Here, we show that electrochemical techniques can be used to measure the surface chemical properties of the self-assembled aggregate structures and also to determine the pK_a of the gelators. We also provide a method to quickly determine whether a functionalised-dipeptide will form a gel or not. This method has scope for use in high-throughput screening and further complex pH-triggered self-assembled gelation systems.