This project aims to develop tools to visualize structures of chitin/chitosan and study how these molecules interact with proteins – all at the single molecule level.

Chitin and chitosan are among the most abundant carbohydrates found on Earth. These molecules hold significant value in many different fields due to their low cost and low toxicity, as well as due to their essential role as structural materials and signaling molecules in many living organisms. Despite its importance, our understanding of chitin/chitosan properties remain limited today due to the sheer difficulties in elucidating their molecular structures. Given that almost every chitin and chitosan molecules has a unique structure, present technology to study their structures performs measurement at millions of molecules at once, making it challenging to observe structural details at the individual level. The challenge of unveiling chitin/chitosan structures calls for a direct, single molecule approach.

This project confronts this challenge by performing direct imaging of individual chitin/chitosan molecules to unveil their structures and chemical interactions at single molecule level. In our approach, chitin/chitosan molecules are adsorbed at a surface and imaged individually by scanning tunnelling microscopy at the nanometer resolution (see Figure). By imaging single chitin/chitosan chains at the nanoscale, we aim to reveal the molecular structure and the chemical interactions present in individual chitin/chitosan chains. We anticipate that direct nanoscale imaging of chitin/chitosan should unveil how they bind to diverse proteins, as well as how they give rise to rich physical properties in chitin/chitosan materials. Understanding chitin/chitosan structures and interactions at single molecule level will provide the molecular origin of the diverse chitin/chitosan properties, thereby contributing towards the development of new therapeutics and materials based on chitin and chitosan.