Development of an aptasensor based on a fluorescent particles-modified aptamer for ochratoxin A detection

Area of Science:

• Analytical Chemistry
• Biotechnology
• Materials Science

Background:

• Aptasensing platforms require efficient signal generation and separation methods.
• Ochratoxin A (OTA) is a significant mycotoxin requiring sensitive detection methods.
• Integrating fluorescent and magnetic particles offers a promising approach for enhanced assays.

Purpose of the Study:

• To develop a generic fluorescent aptasensing design using carboxy-modified fluorescent particles and magnetic particles.
• To establish a sensitive and reliable method for detecting ochratoxin A (OTA).
• To compare displacement and competitive assay formats for improved analytical characteristics.

Main Methods:

• Utilized carboxy-modified fluorescent particles as signal probes and magnetic particles as solid supports.
• Developed aptamer-functionalized magnetic beads for OTA capture.
• Employed fluorescent detection in both displacement and competitive assay formats.
• Validated the aptasensing platform for OTA detection in beer samples.

Main Results:

• Competitive fluorescent assays demonstrated superior analytical performance compared to displacement assays.
• Achieved high sensitivity for OTA detection with a limit of detection (LOD) of 0.005 nM and an IC50 of 7.2 nM.
• Successfully detected OTA in a beer sample matrix, showcasing the platform's practical applicability.

Conclusions:

• The developed generic fluorescent aptasensing platform provides a sensitive and efficient method for OTA detection.
• Competitive assay formats offer improved analytical characteristics for aptasensing applications.
• The proposed design is adaptable for detecting other analytes in various matrices and integrating into diverse fluorescent-based affinity assays.