Coffee ring effect assisted improved S. aureus screening on a physically restrained gold nanoflower enriched SERS...

Area of Science:

• Analytical Chemistry
• Biotechnology
• Environmental Science

Background:

• Conventional water pathogen identification is challenging due to low concentrations and multi-step processes.
• Increasing bioterrorism threats and the need for safe water supplies necessitate advanced detection methods.
• Surface-Enhanced Raman Scattering (SERS) offers high specificity and sensitivity for molecular detection.

Purpose of the Study:

• To develop a highly sensitive and reproducible SERS-based assay for identifying low concentrations of waterborne pathogens.
• To improve SERS analysis by employing a two-level confinement strategy combined with the coffee ring effect.
• To establish a cost-effective and robust method for proactive water pathogen surveillance.

Main Methods:

• Utilized a two-level confinement technique, restricting nanostructure deposition to a small area.
• Leveraged the coffee ring effect for analyte pre-concentration on nanostructures.
• Applied SERS to detect Staphylococcus aureus (S. aureus) and R6G in spiked drinking water samples.

Main Results:

• Achieved a Limit of Detection (LOD) of 10^3 CFU/ml for S. aureus and 10^-12 M for R6G.
• Demonstrated a linear relationship between signal intensity and analyte concentration.
• Exhibited reproducible and non-degenerate signals with low Relative Standard Deviation (RSD) values (8.37% for coffee ring effect).

Conclusions:

• The developed SERS method offers a simple, low-cost, and robust approach for sensitive pathogen detection in water.
• The technique enhances SERS detection sensitivity and has potential for development into a micro total analysis system (μTAS).
• This method provides a significant advancement for proactive water quality monitoring and bioterrorism preparedness.