Label-free aptasensor for platelet-derived growth factor (PDGF) protein

Area of Science:

• Biosensors
• Nanotechnology
• Analytical Chemistry

Background:

• Platelet-derived growth factor (PDGF) is crucial in cell growth and angiogenesis.
• Accurate detection of PDGF is vital for understanding and treating various diseases.
• Existing detection methods often require complex labeling procedures.

Purpose of the Study:

• To develop a label-free aptasensor for sensitive and specific detection of PDGF protein.
• To utilize mixed self-assembled monolayers (SAMs) for enhanced sensor performance.
• To demonstrate the efficacy of electrochemical techniques for monitoring protein-aptamer interactions.

Main Methods:

• Fabrication of a gold electrode modified with a mixed SAM of PDGF-binding aptamer and 6-mercaptohexanol (MCH).
• Electrochemical characterization using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV).
• Utilizing a redox marker ([Fe(CN)(6)](3-/4-)) to detect protein binding events.

Main Results:

• Significant changes in CV peak currents and EIS electron transfer resistance (Rct) upon PDGF binding.
• Successful recognition of PDGF by the aptamer SAM without aptamer modification.
• A linear decrease in DPV signal correlated with PDGF concentrations from 1-40 nM.
• Control experiments confirmed the specificity of the aptasensor.

Conclusions:

• A label-free aptasensor for PDGF detection has been successfully demonstrated.
• The mixed SAM approach provides an effective platform for aptasensor development.
• Electrochemical methods are suitable for real-time monitoring of protein-aptamer complex formation.