Real-time potentiometric detection of bacteria in complex samples

Area of Science:

• Biosensing
• Nanotechnology
• Food Safety

Background:

• Traditional bacterial detection methods are time-consuming and require complex sample preparation.
• Current advanced techniques struggle with rapid, reliable detection in real-world samples.

Purpose of the Study:

• To develop a rapid, label-free, and selective method for detecting living bacteria in complex food matrices.
• To demonstrate the effectiveness of a potentiometric aptamer-based biosensor for bacterial identification.

Main Methods:

• Utilized a potentiometric biosensor with single-walled carbon nanotubes (SWCNTs) as transducers.
• Immobilized aptamers as biorecognition elements for selective bacterial capture.
• Tested the biosensor using *Escherichia coli* (E. coli) CECT 675 as a model organism.

Main Results:

• Achieved label-free detection of bacteria in milk (6 CFU/mL) and apple juice (26 CFU/mL) within minutes.
• Demonstrated high selectivity for both interspecies and interstrain bacterial identification.
• Observed a linear response up to 10^4 CFU/mL with sensor reusability for at least five cycles.

Conclusions:

• The developed aptamer-based biosensor provides a simple, rapid, and selective tool for direct bacterial detection.
• This technology offers a powerful solution for immediate microorganism identification in food safety applications.
• The biosensor exhibits excellent performance, reusability, and ease of use for practical applications.