Hydrophobic interaction and charge accumulation at the diamond-electrolyte interface

Area of Science:

• Materials Science
• Surface Chemistry
• Biosensor Technology

Background:

• Hydrophobic interactions are known but their effect on biosensor devices is under-explored.
• Diamond field-effect devices are promising for biosensing applications.

Purpose of the Study:

• To investigate the influence of surface hydrophobicity on diamond-based biosensor performance.
• To experimentally and computationally study the hydrogen-terminated diamond/aqueous electrolyte interface.

Main Methods:

• Hall effect experiments were performed on diamond field-effect devices.
• Simulations were used to analyze the interfacial potential.
• Interfacial capacitance was derived from gate-dependent Hall carrier concentration.

Main Results:

• The hydrophobic nature of the diamond surface is essential for modeling interfacial capacitance.
• The structure of interfacial water is significantly influenced by surface hydrophobicity.
• Surface hydrophobicity profoundly affects the performance of potentiometric biosensor devices.

Conclusions:

• Understanding and controlling surface hydrophobicity is critical for optimizing biosensor design.
• The findings provide experimental evidence for the impact of hydrophobicity on biosensor operation.
• This work highlights the importance of interfacial water structure in biosensing.