Development of Simple and Rapid Bead-Based Cytometric Immunoassays Using Superparamagnetic Hybrid Core-Shell
Charlie Tobias1, Daniel López-Puertollano1,2, Antonio Abad-Somovilla2
1Chemical and Optical Sensing Division, Bundesanstalt für Materialforschung und -prüfung (BAM), Richard-Willstätter-Str. 11, Berlin D-12489, Germany.
ACS Measurement Science Au
|December 23, 2024
Summary
New superparamagnetic beads accelerate flow cytometry immunoassays for food safety and environmental monitoring. These rapid, sensitive beads offer a 15-minute assay time, enabling point-of-need diagnostics.
Area of Science:
- Biomedical Engineering
- Analytical Chemistry
- Materials Science
Background:
- Flow cytometry immunoassays offer high throughput but are limited by long assay times and complex workflows for applications like food safety.
- There is a need for rapid, simplified bead-based cytometric immunoassays for point-of-need applications, especially with portable cytometers.
- Conventional polymer beads present challenges in assay speed and workflow complexity.
Purpose of the Study:
- To introduce superparamagnetic hybrid polystyrene-silica core-shell microparticles as advanced alternatives to conventional polymer beads.
- To evaluate the performance of these novel beads in competitive cytometric immunoassays.
- To optimize bead-based immunoassays for rapid detection in complex matrices.
Main Methods:
- Development and characterization of superparamagnetic hybrid polystyrene-silica core-shell microparticles.
- Evaluation of bead performance using three different antibodies and binding methods in competitive cytometric immunoassays.
- Optimization of antibody attachment and assay protocol, including magnetic separation for enhanced handling.
- Determination of detection limits and total assay time.
Main Results:
- The hybrid beads demonstrated high specificity, sensitivity, and excellent handling via magnetic separation.
- Secondary antibody binding approach yielded optimal performance with strong, consistent signals and minimal uncertainty.
- Achieved a detection limit of 0.025 nM within a 15-minute total assay time.
- Successfully detected ochratoxin A (OTA) in raw flour samples.
Conclusions:
- Superparamagnetic hybrid polystyrene-silica core-shell microparticles are versatile tools for rapid flow cytometry immunoassays.
- The optimized protocol significantly reduces assay time and complexity, making flow cytometry viable for point-of-need applications.
- These beads have broad implications for food safety, animal health, environmental monitoring, and clinical diagnostics.
