DNA aptamer-functionalized PDA nanoparticles: from colloidal chemistry to biosensor applications

Area of Science:

• Biomedical science
• Nanotechnology
• Electrochemistry
• Biosensing

Background:

• Polydopamine nanoparticles (PDA NPs) offer simple preparation, adhesion, and functionalization capabilities for biomedical applications.
• Existing challenges include PDA NP application as electrode coatings and biomolecule conjugation for electrochemical sensors.

Purpose of the Study:

• To develop an electrochemical interface using PDA NPs conjugated with DNA aptamers for glycated albumin (GA) detection.
• To investigate DNA aptamer-surface interactions on PDA NPs via molecular dynamics (MD) simulation.

Main Methods:

• Synthesized PDA NPs via dopamine oxidation and conjugated them with anti-GA DNA aptamers.
• Deposited PDA NP-aptamer conjugates on screen-printed carbon electrodes (SPCEs).
• Characterized the interface using TEM, SEM, DLS, FTIR, and Raman spectroscopy.
• Employed MD simulations to study aptamer-PDA surface interactions.

Main Results:

• PDA NP-coated SPCEs exhibited decreased charge transfer resistance, indicating conductivity.
• Characterization confirmed spherical PDA NPs and successful aptamer conjugation.
• The developed electrochemical interface detected GA with a detection limit of 0.17 μg/mL.
• MD simulations revealed a stable, perpendicular orientation of the aptamer on the PDA surface.

Conclusions:

• The study presents a functional electrochemical interface based on PDA NPs and DNA aptamers for GA detection.
• Findings provide insights into aptamer-PDA surface interactions, aiding future biosensor design.
• The developed interface shows potential for point-of-care diagnostic applications.