A sensitive electrochemiluminescent biosensor based on AuNP-functionalized ITO for a label-free immunoassay of...

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Clinical Diagnostics

Background:

• C-peptide is a co-product of insulin secretion by pancreatic β-cells.
• C-peptide levels in body fluids are closely linked to diabetes mellitus.
• Accurate and sensitive C-peptide detection is crucial for diabetes management.

Purpose of the Study:

• To develop a simple, sensitive, and specific label-free electrochemiluminescent (ECL) immunosensor for C-peptide quantification.
• To establish a versatile platform for diabetes clinical diagnosis, classification, and research.

Main Methods:

• Fabrication of an indium tin oxide (ITO) electrode decorated with gold nanoparticles (AuNPs) using (3-aminopropyl)trimethoxysilane.
• Immobilization of anti-C-peptide antibodies onto the AuNP-modified electrode.
• Quantification of C-peptide via label-free ECL signaling using luminol as the probe, measuring ECL inhibition.

Main Results:

• The fabricated electrode's characteristics were confirmed using electron microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy.
• The immunosensor achieved a wide linear detection range for C-peptide from 0.05 ng/mL to 100 ng/mL.
• A low detection limit of 0.0142 ng/mL was achieved, demonstrating high sensitivity.

Conclusions:

• The developed label-free ECL immunosensor provides a sensitive and specific method for C-peptide detection.
• This strategy represents a promising and versatile platform for diabetes-related clinical applications and research.
• The assay's simplicity and effectiveness support its potential for widespread adoption in diagnostics.