Nanoplasmonic SERS on fidget spinner for digital bacterial identification

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Nanotechnology

Background:

• Raman spectroscopy provides sensitive molecular insights for bacterial analysis but faces challenges in accuracy and reproducibility due to bulk signals and analyte heterogeneity.
• Existing methods struggle to achieve clinically relevant quantitative data for bacterial detection and identification.

Purpose of the Study:

• To introduce an innovative diagnostic tool, the plasmonic fidget spinner (P-FS), for simultaneous bacterial filtration and ultrasensitive detection.
• To enhance the sensitivity and accuracy of Raman spectroscopy for bacterial identification and quantification.

Main Methods:

• Fabrication of a plasmonic array patterned nitrocellulose membrane using photolithography, integrated into a customized fidget spinner.
• Utilizing nanoplasmonic hotspots on the P-FS to enhance Raman scattering signals (Surface-Enhanced Raman Spectroscopy - SERS).
• Testing the P-FS device with diverse bacterial species (e.g., E. coli, S. aureus) and analyzing SERS intensity mappings.

Main Results:

• Successful identification of various bacterial species based on unique Raman fingerprints using the P-FS device.
• Demonstrated significant enhancement in detection sensitivity due to bacterial interaction with nanoplasmonic hotspots.
• Transformed SERS intensity mappings into digital signals for bacterial identification and quantification using a threshold-based approach.

Conclusions:

• The P-FS device significantly enhances vibrational signatures, enabling reliable and ultrasensitive detection of bacteria.
• Nanoplasmonic-enhanced Raman spectroscopy, utilizing the P-FS, shows strong potential for clinical applications in diagnostics.
• Scalable fabrication of the P-FS under routine conditions facilitates its transition from research to practical use.