Related Experiment Video
Updated: Jul 7, 2026
Multimodal Analytical Platform on a Multiplexed Surface Plasmon Resonance Imaging Chip for the Analysis of Extracellular Vesicle Subsets
Published on: March 17, 2023
Microchannel chips for the multiplexed analysis of human immunoglobulin G-antibody interactions by surface plasmon
Yi Dong1, Thomas Wilkop, Danke Xu
1Department of Chemistry, University of California, Riverside, CA 92521, USA.
Insights
This study introduces a novel method for simultaneously analyzing antigen-antibody interactions using surface plasmon resonance imaging (SPRi) and microfluidic chips. The technique enables sensitive, label-free detection of human immunoglobulin G (IgG) in complex samples like serum.
Area of Science:
- Biotechnology
- Analytical Chemistry
- Immunosensor Technology
Background:
- Accurate quantification of antigen-antibody interactions is crucial for diagnostics and drug development.
- Existing methods often lack the throughput, sensitivity, or multiplexing capabilities required for complex biological samples.
Purpose of the Study:
- To develop and validate a multiplexed surface plasmon resonance imaging (SPRi) method for simultaneous analysis of human immunoglobulin G (IgG) interactions.
- To enable sensitive and label-free detection of IgG in complex matrices such as serum.
Main Methods:
- Fabrication of a multichannel microfluidic chip using poly(dimethylsiloxane) (PDMS) for precise analyte delivery.
- Construction of a sensing interface utilizing avidin-biotin complex for immobilizing biotinylated antibodies.
- Simultaneous screening of four mouse anti-human IgG antibodies using SPR imaging under identical conditions.
- Quantitative analysis of binding affinities via Langmuir adsorption isotherms and kinetic analysis.
Main Results:
- Successfully identified two IgG samples with higher binding affinities to the target.
- Achieved a limit of detection (LOD) of 6.7 nM for IgG in treated serum samples.
- Demonstrated minimization of nonspecific adsorption for direct protein measurement in serum.
Conclusions:
- The combined SPR imaging and multichannel PDMS chip system provides a flexible and convenient platform for sensitive, label-free protein-protein interaction analysis.
- This high-throughput approach is suitable for screening pharmaceutically significant molecules and analyzing complex biological samples.
Abstract:
We report the multiplexed, simultaneous analysis of antigen-antibody interactions that involve human immunoglobulin G (IgG) on a gold substrate by the surface plasmon resonance imaging method. A multichannel, microfluidic chip was fabricated from poly(dimethylsiloxane) (PDMS) to selectively functionalize the surface and deliver the analyte solutions. The sensing interface was constructed using avidin as a linker layer between the surface-bound biotinylated bovine serum albumin and biotinylated anti-human IgG antibodies. Four mouse anti-human IgG antibodies were selected for evaluation and the screening was achieved by simultaneously monitoring protein-protein interactions under identical conditions. Antibody-antigen binding affinities towards human immunoglobulin were quantitatively compared by employing Langmuir adsorption isotherms for the analysis of SPRi responses obtained under equilibrium conditions. We were able to identify two IgG samples with higher affinities towards the target, and the determined binding kinetics falls within the typical range of values reported in the literature. Direct measurement of proteins in serum samples by SPR imaging was achieved by developing methods to minimize nonspecific adsorption onto the avidin-functionalized surface, and a limit of detection (LOD) of 6.7 nM IgG was obtained for the treated serum samples. The combination of SPR imaging and multichannel PDMS chips offers convenience and flexibility for sensitive and label-free measurement of protein-protein interactions in complex conditions and enables high-throughput screening of pharmaceutically significant molecules.
