Mesoporous Gold: Substrate-Dependent Growth Dynamics, Strain Accumulation, and Electrocatalytic Activity for...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Understanding crystal growth dynamics and redox reactions is crucial for optimizing mesoporous materials in electrochemical sensing.
• Substrate properties significantly influence the growth orientation and defect formation in crystalline films.
• Mesoporous gold (mAu) films are promising for electrochemical applications due to their high surface area and conductivity.

Purpose of the Study:

• To investigate the effect of amorphous glass substrates on the growth of mesoporous gold (mAu) films.
• To explore how suppressed crystal growth orientation impacts surface defects and electrochemical activity.
• To demonstrate the enhanced sensing performance of glass-grown mAu films for disease-specific biomolecules.

Main Methods:

• Fabrication of mesoporous gold (mAu) films on amorphous glass substrates.
• Analysis of crystal growth orientation and strain accumulation using advanced characterization techniques.
• Electrochemical measurements to evaluate sensing performance and limit of detection (LoD) for specific RNA targets.

Main Results:

• Amorphous glass substrates suppressed the typical <111> oriented growth of mAu films.
• Suppressed growth led to increased strain and abundant surface defects, enhancing electrochemical activity.
• The fabricated mAu film exhibited significantly accelerated diffusion and high sensitivity for electrochemical detection.

Conclusions:

• Glass substrates offer a unique approach to control mAu film morphology and enhance electrochemical properties.
• The generated surface defects are key to improved electrochemical sensing performance.
• The developed mAu film demonstrates exceptional sensitivity for detecting SARS-CoV-2 RNA at attomolar levels.