A bioelectrode for penicillin detection based on gluten-membrane-entrapped microbial cells

Area of Science:

• Biotechnology
• Biosensors
• Microbial Electrochemistry

Background:

• Development of sensitive and cost-effective biosensors for antibiotic detection is crucial.
• Traditional methods often rely on purified enzymes, increasing costs and complexity.
• Microbial immobilization offers an alternative for enzyme-based detection systems.

Purpose of the Study:

• To establish a bioelectrode for penicillin detection using immobilized microbial cells.
• To investigate the use of gluten as an inexpensive immobilization matrix.
• To optimize the bioelectrode performance for penicillin G detection.

Main Methods:

• Entrapment of penicillinase-synthesizing Escherichia coli cells within a gluten-oxidized starch gel matrix.
• Fabrication of a bioelectrode membrane with controlled thickness and cell content.
• Testing the bioelectrode response to varying penicillin G concentrations under different conditions.
• Evaluation of cell permeabilization techniques to enhance enzyme accessibility.

Main Results:

• A linear response of the bioelectrode to penicillin G (1-16 mM) was achieved with a steady response time under 3 minutes.
• Gluten membrane immobilization provided a cost-effective alternative to purified enzymes.
• Cell permeabilization shortened response time but reduced overall enzyme activity and steady response.
• Bioelectrode performance was influenced by pH and buffer concentration.

Conclusions:

• A functional microbial bioelectrode for penicillin G detection was successfully developed using immobilized E. coli in a gluten matrix.
• The developed bioelectrode presents a promising, low-cost approach for penicillin sensing.
• Further optimization is needed to balance response time and enzyme activity after cell permeabilization.