Electrochemical Immunoassay Using Open Circuit Potential Detection Labeled by Platinum Nanoparticles

Area of Science:

• Electrochemistry
• Nanotechnology
• Biosensors

Background:

• Electrochemical immunoassays are crucial for detecting biomarkers.
• Platinum nanoparticles (PtNPs) offer unique electrochemical properties.
• Open circuit potential (OCP) detection presents a simplified electrochemical measurement approach.

Purpose of the Study:

• To develop a simple electrochemical immunoassay for human chorionic gonadotropin (hCG) detection.
• To utilize platinum nanoparticles (PtNPs) and open circuit potential (OCP) for sensitive and direct electrical detection.
• To demonstrate the feasibility of using disposable screen-printed carbon electrodes (SPCEs) for a cost-effective diagnostic tool.

Main Methods:

• Development of a sandwich-type electrochemical immunoassay on disposable screen-printed carbon electrodes (SPCEs).
• Detection of human chorionic gonadotropin (hCG) using platinum nanoparticles (PtNPs) and open circuit potential (OCP) measurement.
• Utilized the electrocatalytic oxidation of hydrazine on PtNPs for signal generation.

Main Results:

• Achieved a low detection limit of 0.28 ng mL⁻¹ for hCG.
• Established a linear detection range from 0 to 10 ng mL⁻¹.
• Demonstrated a simple, potential-free electrochemical detection method with acceptable sensitivity and reproducibility.

Conclusions:

• The developed PtNP-based OCP immunoassay is a simple, sensitive, and cost-effective method for hCG detection.
• The use of disposable SPCEs and minimal sample volume (2 μL) makes it suitable for point-of-care applications.
• This approach offers potential for simplified and miniaturized diagnostic systems with minimal user intervention.