Microfluidic device for concentration and SERS-based detection of bacteria in drinking water

Area of Science:

• Analytical Chemistry
• Microfluidics
• Biosensing

Background:

• Traditional bacterial identification methods in drinking water are time-consuming and complex.
• There is a need for rapid, easy-to-operate, and cost-effective detection systems.
• Lab-on-a-chip devices offer potential for portable and efficient analysis.

Purpose of the Study:

• To develop and characterize a disposable microfluidic chip for rapid bacterial pathogen detection.
• To integrate electrokinetic concentration with surface-enhanced Raman spectrometry (SERS) for enhanced sensitivity.
• To demonstrate the device's functionality using common bacterial pathogens in spiked tap water.

Main Methods:

• Fabrication of a disposable lab-on-a-chip device with perpendicular microfluidic channels and a nanoporous membrane.
• Utilizing potential-driven forces for electrokinetic concentration of bacteria.
• Employing silver nanoparticles to enhance surface-enhanced Raman spectrometry (SERS) signals.
• Analyzing spiked tap water samples for bacterial pathogens (Escherichia coli, Pseudomonas taiwanensis).

Main Results:

• The microfluidic chip successfully trapped bacteria and silver nanoparticles on the nanoporous membrane.
• Optimized experimental parameters enabled sensitive SERS detection of bacterial pathogens.
• The device demonstrated reliable and rapid identification of common pathogens in spiked tap water.
• The system effectively coupled electrokinetic concentration with SERS detection.

Conclusions:

• The developed lab-on-a-chip device is a promising platform for rapid and reliable bacterial pathogen detection in drinking water.
• The integration of microfluidics, electrokinetics, and SERS offers a sensitive and efficient analytical approach.
• This disposable optical platform has the potential for field deployment and water quality monitoring.