Grafting odorant binding proteins on diamond bio-MEMS

Area of Science:

• Biochemistry
• Materials Science
• Sensor Technology

Background:

• Odorant binding proteins (OBPs) are crucial for detecting odorant molecules in olfactory systems.
• Polycrystalline diamond surfaces offer promising potential as chemical transducers for biosensors.

Purpose of the Study:

• To investigate two chemical grafting methods for immobilizing porcine OBPs onto polycrystalline diamond surfaces.
• To develop improved biosensors for artificial olfaction applications.

Main Methods:

• Chemically grafting OBPs onto diamond surfaces using two distinct approaches.
• Utilizing histidine-tag complexation with nickel for controlled protein orientation.
• Characterizing protein immobilization via electrochemical impedance spectroscopy, fluorescence imaging, and X-ray photoelectron spectroscopy.

Main Results:

• The second grafting method, employing nickel-histidine tag complexation, enabled controlled protein orientation.
• This controlled orientation resulted in approximately 20% more sensitive sensors compared to random immobilization.
• Enhanced sensitivity is attributed to improved ligand access to protein active sites and potentially higher immobilization yields.

Conclusions:

• Controlled orientation of OBPs on diamond surfaces significantly enhances biosensor performance.
• The developed grafting method is highly promising for studying OBP ligand binding properties.
• This approach facilitates the development of non-specific biosensor arrays for artificial olfaction.