A self-assembly aptasensor based on thick-shell quantum dots for sensing of ochratoxin A

Area of Science:

• * Nanotechnology
• * Biosensing
• * Analytical Chemistry

Background:

• * Ochratoxin A (OTA) is a prevalent food contaminant with significant health risks.
• * Existing methods for OTA detection can be time-consuming and lack sensitivity.
• * Development of rapid, sensitive, and reliable detection methods is crucial for food safety.

Purpose of the Study:

• * To fabricate a novel self-assembling aptasensor for the detection of ochratoxin A (OTA).
• * To utilize thick-shell quantum dots (QDs) and aptamers for enhanced sensing capabilities.
• * To achieve sensitive and selective monitoring of OTA in food matrices.

Main Methods:

• * Synthesis of CdSe/CdS core/shell quantum dots with high photoluminescence quantum yields.
• * Fabrication of a tunable-valency aptasensor by attaching phosphorothioate-modified capture aptamers to QDs.
• * Implementation of a fluorescence resonance energy transfer (FRET) system for signal generation upon OTA binding.

Main Results:

• * The developed aptasensor demonstrated a low detection limit of 0.5 ng mL(-1) for OTA.
• * A linear detection range of 1 to 30 ng mL(-1) was achieved, suitable for practical applications.
• * The aptasensor exhibited effectiveness, rapidity, and anti-interference capabilities.

Conclusions:

• * The novel self-assembling aptasensor provides a highly sensitive and effective platform for OTA detection.
• * Thick-shell QDs offer a superior alternative for sensitive bioimaging and illumination applications.
• * This technology meets the demands for rapid and reliable monitoring of food contaminants.