Selective Antibody-Free Sensing Membranes for Picogram Tetracycline Detection

Area of Science:

• Electrochemistry
• Sensing Technology
• Analytical Chemistry

Background:

• Antibiotic residues, such as tetracycline (TC), in food products pose significant health risks.
• Current detection methods often rely on antibodies, which can be costly and have limited shelf-life.
• Development of sensitive, antibody-free sensing platforms is crucial for effective food safety monitoring.

Purpose of the Study:

• To develop and characterize an antibody-free sensing membrane for the sensitive detection of tetracycline.
• To utilize electrochemical impedance spectroscopy (EIS) for tetracycline quantification.
• To evaluate the sensor's performance, including detection limit, selectivity, and stability.

Main Methods:

• Formulation of a PVC membrane doped with a tetracycline/ion-pair ([3,3'-Co(1,2-C2B9H11)2]- or [o-COSAN]-).
• Deposition of the membrane onto a single-walled carbon nanotube (SWCNT) modified gold microelectrode.
• Detection of tetracycline using electrochemical impedance spectroscopy (EIS).

Main Results:

• Achieved a highly sensitive detection limit of 0.3 pg/L for tetracycline.
• Demonstrated superior sensitivity for tetracycline compared to other related antibiotics (oxytetracycline, terramycin, demeclocycline).
• The sensor exhibited a shelf-life exceeding six months and was successfully applied to detect tetracycline in spiked honey samples.

Conclusions:

• The developed antibody-free PVC membrane sensor offers a sensitive, selective, and stable platform for tetracycline detection.
• This technology paves the way for continuous monitoring sensors that are easy to clean and provide direct measurements.
• Eliminates the need for antibodies, reducing costs and improving sensor longevity.