Dual SERS-enhanced core-shell-satellite assemblies with Cu-doped ZIF-8 interlayer for OTA detection

Area of Science:

• Analytical Chemistry
• Materials Science
• Food Science

Background:

• Ochratoxin A (OTA) is a prevalent, toxic mycotoxin in grains, posing significant food safety risks.
• Current detection methods for OTA often lack the sensitivity and speed required for effective food safety monitoring.

Purpose of the Study:

• To develop a novel core-shell-satellite Surface-Enhanced Raman Spectroscopy (SERS) probe for highly sensitive and rapid Ochratoxin A detection.
• To enhance the electromagnetic and chemical signal amplification for improved detection limits.

Main Methods:

• Fabrication of a core-shell-satellite SERS probe (Au@Ag@(Cu-ZIF-8)-AuNPs) with a gold-silver core, copper-doped ZIF-8 coating, and gold nanosatellites.
• Utilizing plasmonic coupling for electromagnetic enhancement and Cu doping in ZIF-8 for chemical signal amplification.
• Testing the probe's performance for Ochratoxin A detection using SERS.

Main Results:

• The developed Au@Ag@(Cu-ZIF-8)-AuNPs probe exhibited dual electromagnetic-chemical enhancement.
• Achieved an ultralow detection limit of 0.057 fg/mL for Ochratoxin A.
• Demonstrated a wide dynamic detection range from 0.1 fg/mL to 1.0 μg/mL, surpassing conventional methods.

Conclusions:

• The novel SERS probe provides a highly sensitive and rapid method for Ochratoxin A detection.
• This technology offers a promising platform for effective mycotoxin monitoring in food safety applications.
• The study advances SERS-based detection technologies for critical food safety concerns.