Electron transfer through protein-bound water and its bioelectronic application.

Area of Science:

• Biomaterials Science
• Conductive Polymers
• Bioelectronics

Background:

• Traditional conductive materials often rely on metallic or redox-active components, limiting biocompatibility.
• Polypeptides, like gelatin, possess inherent structures capable of interacting with water molecules.

Purpose of the Study:

• To investigate the electron conductivity of polypeptide-water metastructures.
• To explore the role of bound water in facilitating electron transfer in polypeptides.
• To assess the potential of these materials for nonvolatile resistive memory applications.

Main Methods:

• Utilized gelatin as a model polypeptide due to its hydrogen bonding capabilities.
• Employed Raman spectroscopy to analyze the composition of the conductive metastructure.
• Investigated the effect of bound water removal on electron conductivity.
• Evaluated the resistive memory characteristics of the gelatin hydrogel.

Main Results:

• A metastructure of unwound gelatin polypeptides and bound water exhibited high and stable electron conductivity.
• Removal of bound water significantly reduced electron conductivity, highlighting its critical role.
• The gelatin hydrogel demonstrated switchable states between low and high conductivity, enabling rewritable nonvolatile resistive memory.
• Achieved a high ON/OFF current ratio of 10^5 at a low reading voltage (0.09 V).

Conclusions:

• Bound water is essential for long-distance electron transfer in polypeptide-based metastructures.
• This phenomenon provides a new paradigm for designing biocompatible conductive materials.
• The developed gelatin hydrogel exhibits promising performance for bioelectronic memory devices.