A fluorescent aptasensor for ochratoxin A detection based on enzymatically generated copper nanoparticles with a...

Area of Science:

• Analytical Chemistry
• Biotechnology
• Nanotechnology

Background:

• Ochratoxin A (OTA) is a common mycotoxin found in food and beverages, posing significant health risks.
• Accurate and sensitive detection methods for OTA are crucial for food safety regulations.
• Existing methods for OTA detection can be complex and time-consuming.

Purpose of the Study:

• To develop a novel fluorescence enhancement method for the sensitive determination of ochratoxin A (OTA).
• To utilize aptamer-functionalized magnetic beads and enzymatically synthesized polythymine-coated copper nanoparticles (CuNPs) for OTA detection.
• To establish a rapid and reliable assay for OTA quantification in real-world samples.

Main Methods:

• Immobilization of OTA-binding aptamers on magnetic beads for selective capture.
• Induction of aptamer structural changes upon OTA binding, leading to the release of a complementary DNA strand (cDNA).
• Enzymatic generation of polythymine using cDNA as a primer, followed by synthesis of polythymine-coated CuNPs for fluorescence detection.

Main Results:

• The developed method demonstrated high sensitivity with a detection limit of 2.0 nM for OTA.
• The assay showed successful application in determining OTA levels in spiked diluted red wine samples.
• The fluorescence signal was directly correlated with the concentration of OTA due to the formation of CuNPs.

Conclusions:

• The proposed fluorescence enhancement method provides a sensitive and efficient approach for OTA determination.
• The use of aptamer-magnetic beads and CuNPs offers a promising platform for developing rapid biosensors.
• This method has potential for routine monitoring of OTA in food and beverages to ensure consumer safety.