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In situ Tracking of Exoenzyme Activity Using Droplet Luminescence Concentrators for Ratiometric Detection of
Agata W Baryzewska1, Christian Roth2, Peter H Seeberger2
1Department of Colloid Chemistry, Max Planck Institute of Colloids and Interfaces, Am Muehlenberg 1, 14476 Potsdam, Germany.
ACS Sensors
|November 7, 2023
Summary
This study introduces a novel biosensing method using Janus emulsion droplets to detect bacterial pathogens. This rapid, cost-effective technique visualizes enzyme activity for pathogen identification without antibodies or DNA.
Area of Science:
- Biotechnology
- Analytical Chemistry
- Microbiology
Background:
- Bacterial pathogens pose significant risks to public health, necessitating rapid and accurate detection methods.
- Existing biosensing technologies often require complex procedures, expensive reagents, or specialized equipment, limiting their widespread application.
- Enzyme activity is a key indicator of bacterial viability and metabolic function, making it a promising target for biosensing.
Purpose of the Study:
- To develop a novel, rapid, and cost-effective biosensing paradigm for bacterial pathogen identification.
- To demonstrate the utility of biphasic Janus emulsion droplets as a platform for in situ visualization of bacterial exoenzyme activity.
- To establish a sensitive and specific detection method for common foodborne pathogens.
Main Methods:
- Utilized biphasic Janus emulsion droplets functionalized with enzyme-cleavable surfactants.
- Exploited enzyme-induced surfactant cleavage to alter droplet interfacial tension and internal morphology.
- Employed angle-dependent anisotropic fluorescence emission for macroscopic signal transduction and detection.
- Quantified pathogen levels using colony-forming units per milliliter (CFU mL⁻¹).
Main Results:
- Achieved rapid (<4 hours) and cost-effective identification of bacterial pathogens.
- Demonstrated antibody- and DNA-free detection, simplifying the assay.
- Established low detection thresholds: <10 CFU mL⁻¹ for *Salmonella* and <10² to 10³ CFU mL⁻¹ for *Listeria* and *Escherichia coli*.
- Showcased Janus droplets as effective optical transducers and signal amplifiers.
Conclusions:
- The developed Janus emulsion droplet system offers a powerful and versatile platform for bacterial biosensing.
- This novel approach provides a sensitive, rapid, and cost-effective alternative for detecting foodborne pathogens.
- The method's simplicity and efficiency hold promise for point-of-care diagnostics and environmental monitoring.
