Dynamic light scattering biosensing based on analyte-induced inhibition of nanoparticle aggregation
A D Levin1, A Ringaci2, M K Alenichev3
1All-Russian Research Institute for Optical and Physical Measurements, 46 Ozernaya st., 119361, Moscow, Russia. levin-ad@vniiofi.ru.
Analytical and Bioanalytical Chemistry
|April 13, 2020
Summary
A novel dynamic light scattering biosensing method enables direct, quantitative detection of small molecules like the antibiotic chloramphenicol. This simple, rapid assay offers high sensitivity and a wide dynamic range for food safety diagnostics.
Area of Science:
- Analytical Chemistry
- Nanotechnology
- Biosensing
Background:
- Direct quantitative detection of small molecules (haptens) is crucial for diagnostics.
- Existing methods often require complex procedures or lack sensitivity.
- Nanoparticle aggregation assays offer potential for sensitive detection.
Purpose of the Study:
- To develop a direct quantitative detection method for small molecules using dynamic light scattering (DLS) biosensing.
- To implement a homogeneous competitive immunoassay for enhanced simplicity and speed.
- To evaluate the performance of the DLS biosensing technique for food safety applications.
Main Methods:
- Utilized dynamic light scattering (DLS) for nanoparticle-based detection.
- Implemented a homogeneous competitive immunoassay format.
- Optical detection of analyte-induced inhibition of nanoparticle aggregation.
- Validated the assay in buffer and milk matrices for chloramphenicol detection.
Main Results:
- Achieved high specificity, sensitivity (LOD in milk: 2.4 ng/mL), precision (4.0 ± 1.2%), and ruggedness (8.3%).
- Demonstrated excellent recovery (96%) and a wide dynamic range (3 orders of magnitude).
- The assay requires no washing step and has a short assay time.
Conclusions:
- The developed DLS biosensing technique provides a robust platform for direct quantitative detection of small molecules.
- The assay's simplicity, speed, and performance characteristics make it suitable for point-of-care and field-oriented diagnostics.
- This approach holds promise for enhancing food safety diagnostics and other analytical applications.
