Rapid Colorimetric Antibody Detection Using a Dual-function Peptide Probe for Silver Nanoparticle Aggregation and...

Area of Science:

• Biotechnology
• Nanotechnology
• Analytical Chemistry

Background:

• Therapeutic monoclonal antibody development requires efficient antibody detection tools.
• Existing methods can be time-consuming or require complex procedures.
• Label-free assays are desirable for simplifying detection processes.

Purpose of the Study:

• To develop a simple, rapid, and label-free colorimetric assay for antibody detection.
• To utilize a synthetic cationic antibody-recognizing peptide for this purpose.
• To investigate the potential of this assay for high-throughput screening.

Main Methods:

• A synthetic peptide (NKFRGKYK) with IgG-binding and cationic properties was employed.
• The assay involved mixing the peptide with silver nanoparticles (AgNPs) and the sample.
• Color changes in the AgNP solution indicated IgG presence due to particle aggregation/dispersion.

Main Results:

• The assay successfully detected immunoglobulin G (IgG) in culture media.
• Detection was achieved within 2 minutes for IgG concentrations ranging from 100 to 500 nM.
• The colorimetric response was attributed to electrostatic interactions between the cationic peptide and anionic AgNPs upon IgG binding.

Conclusions:

• The developed assay provides a fast and readily observable method for IgG detection.
• This approach shows promise for high-throughput selection of IgG-producing cells.
• The assay avoids complex nanoparticle functionalization, offering a simplified detection strategy.