Nanoscale investigation of silk proteins using near-field optics

Recent developments in nanotechnology have led to renewed interest and breakthroughs in structural biopolymers, specifically silk protein, as functional materials. The exceptional mechanical properties and the bio-compatibility of silk has enabled wide range of applications from biomedical devices, optics, electronics, to transient implants. Understanding the mechanisms that underpin the β-sheet formation and deformation as well as the formulation of strategies to control inter- and intramolecular bonds within silk protein matrices is paramount for the control of protein structures and the improvement of material properties. However, conventional imaging techniques that are used to characterize and recapitulate silk structure–function relationships present challenges at the nanoscale given their limitations in chemical sensitivity (for example, electron microscopy and atomic force microscopy (AFM)) or limited spatial resolution (for example, ‘far-field’ infrared (IR) spectroscopy). In this context, my research focuses on the understanding of the conformational transitions of silk fibroin and recombinant spider silk, and the interaction between the protein and energy or other biomolecules at nanoscale using near-field optics. In particular, the complete conformational transition of the silk protein under the electron bombardment have been visualized, guiding the creation of novel 3D nanostructures using Electron Beam Lithography (EBL). Meanwhile, the dual-tone structural formation of silk structures under ion beam irradiation have been thoroughly investigated, resulting in the “Protein Lego” manufacturing paradigm. The UV enabled silk protein cross-linking has also been utilized for scalable manufacturing of bio-structures. The interaction between the silk protein and other types of biological materials (such as cells, bacteria, and virus) has been studied to explore the stabilization capability of the silk matrix. The comprehensive investigation of the interplay between the protein material, energy input, as well as other chemical/biological species will pave the way for the bio-compatible, bio-degradable, and multi-functional platforms, serving as the building blocks of the green bio-manufacturing paradigm