Fast and sensitive detection of an anthrax biomarker using SERS-based solenoid microfluidic sensor

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Biosensing Technologies

Background:

• Anthrax detection relies on identifying specific biomarkers like poly-γ-D-glutamic acid (PGA).
• Existing detection methods may lack the sensitivity or automation required for rapid field analysis.
• Microfluidic devices offer miniaturized platforms for enhanced analytical performance.

Purpose of the Study:

• To develop and validate a fully automated microfluidic device for sensitive and quantitative detection of PGA.
• To integrate surface-enhanced Raman scattering (SERS) with microfluidics for enhanced anthrax biomarker analysis.
• To improve assay reliability by incorporating a control channel for external standardization.

Main Methods:

• A solenoid-embedded microfluidic device was engineered for automated sample processing.
• Competitive reaction assay utilizing PGA-conjugated gold nanoparticles and anti-PGA magnetic beads.
• Magnetic immunocomplexes were trapped and analyzed via SERS.
• A control channel measured PGA-free serum to correct for experimental variations.

Main Results:

• The SERS-based microfluidic sensor successfully detected PGA in solution.
• The assay demonstrated high sensitivity with a limit of detection (LOD) of 100 pg/mL for PGA in serum.
• The integrated control channel significantly improved measurement accuracy and reliability.

Conclusions:

• The automated SERS-microfluidic device provides a sensitive and reliable method for PGA detection.
• This technology represents a valuable analytical tool for anthrax-related aqueous sample analysis.
• The approach holds potential for rapid and quantitative detection of biological threats.