Carbonyl mediated conductance through metal bound peptides: a computational study

Area of Science:

• Molecular electronics
• Computational chemistry
• Biophysics

Background:

• Experimental studies show significant conductance increases in peptides upon metal ion binding.
• Understanding the precise mechanism behind this conductance switching is crucial for molecular electronics applications.

Purpose of the Study:

• To computationally investigate the mechanism of conductance switching in metal-ion-bound peptides.
• To identify the key factors contributing to the observed large conductance improvements.

Main Methods:

• Density Functional Theory (DFT) calculations were employed to model metal-peptide complexes.
• Simulations examined the electronic structure and configurational changes upon applying bias potential.
• Analysis focused on molecular orbitals and interactions with electrode leads.

Main Results:

• Metal ion oxidation after binding to the peptide, induced by bias potential, is identified as a key factor.
• A combination of configurational changes, metal ion redox activity, and interactions with gold leads is necessary for conductance enhancement.
• Distinct molecular orbital differences between nickel and copper complexes explain variations in conductance improvement.

Conclusions:

• The study elucidates the atomistic mechanism of conductance switching in metal-peptide systems.
• Computational findings provide insights into designing molecular electronic devices based on peptide-metal interactions.
• Understanding metal ion redox states and their interplay with peptide conformation is vital for controlling molecular conductance.