Myoglobin-loaded layer-by-layer films containing SiO(2) nanoparticles studied using electrochemistry

Area of Science:

• Materials Science
• Electrochemistry
• Biotechnology

Background:

• Layer-by-layer (LbL) assembly is a versatile technique for fabricating thin films.
• Nanoparticles offer unique properties for film modification and protein immobilization.
• Myoglobin (Mb) is a heme protein with important electrochemical and biological functions.

Purpose of the Study:

• To develop novel protein-loaded LbL films using silica nanoparticles (SiO(2)) for enhanced myoglobin (Mb) loading and electrochemical activity.
• To investigate the influence of nanoparticle incorporation on film porosity and protein diffusion.
• To compare the performance of nanoparticle-based LbL films with traditional polyelectrolyte films.

Main Methods:

• Fabrication of {PDDA/SiO(2)}(n) LbL films by alternate adsorption of poly(diallyldimethylammonium) (PDDA) and SiO(2) nanoparticles.
• Loading of myoglobin (Mb) into the fabricated films.
• Electrochemical characterization using cyclic voltammetry to monitor the Mb heme Fe(III)/Fe(II) redox couple.
• Surface morphology analysis using Scanning Electron Microscopy (SEM).

Main Results:

• {PDDA/SiO(2)}(n) LbL films exhibited significantly improved porosity compared to {PDDA/PSS}(n) films.
• The enhanced porosity of nanoparticle films led to superior electrochemical and electrocatalytic responses of loaded myoglobin.
• Electrostatic interactions were identified as the primary driving force for Mb diffusion into the films.
• Hydrophobic interactions were found to be crucial for stabilizing Mb within the films.

Conclusions:

• Nanoparticle-based LbL films provide a promising platform for efficient protein loading and enhanced electrochemical applications.
• The use of rigid nanoparticles in LbL assembly can overcome the limitations of soft polyelectrolyte films in terms of porosity and protein accessibility.
• Understanding the interactions governing protein loading and stabilization is key to designing advanced biomaterials.