A Highly Sensitive Electrochemical Immunosensor Based on Core-Shell SiO₂-PEI@Ag NPs Nanocomposites for MPA Detection

Area of Science:

• Analytical Chemistry
• Nanotechnology
• Food Science

Background:

• Veterinary drug residues, like medroxyprogesterone acetate (MPA), in animal products raise food safety concerns.
• Conventional MPA detection methods are complex, costly, and time-consuming.
• Electrochemical immunosensors offer a sensitive and efficient alternative for residue analysis.

Purpose of the Study:

• To develop a highly sensitive electrochemical immunosensor for detecting trace amounts of MPA.
• To utilize core-shell SiO2-PEI@Ag nanoparticles for enhanced sensing performance.
• To validate the immunosensor's effectiveness in real food samples.

Main Methods:

• Fabrication of a core-shell SiO2-PEI@Ag nanoparticle-based electrochemical sensing platform.
• Immobilization of specific antibodies onto the nanoparticle surface for MPA recognition.
• Electrochemical detection of MPA using the developed immunosensor.

Main Results:

• The immunosensor achieved a low limit of detection (0.014 ng/mL) and a wide linear range (0.03-100 ng/mL).
• High recovery rates (91.32-102.54%) were observed in pork and milk samples.
• Negligible cross-reactivity with similar steroid hormones and antibiotics was confirmed.

Conclusions:

• The developed electrochemical immunosensor provides a sensitive, accurate, and stable method for MPA detection.
• This technology shows significant potential for routine screening of MPA residues in animal-derived foods.
• It offers a promising complement to conventional analytical techniques for enhanced food safety assurance.