Chemically imaging bacteria with super-resolution SERS on ultra-thin silver substrates.

Area of Science:

• Nanophotonics
• Super-resolution microscopy
• Chemical imaging

Background:

• Plasmonic hotspots in SERS create blinking effects suitable for STORM.
• STORM algorithms can be adapted with diffraction gratings to extract SERS spectra.
• Simultaneous spatial and spectral information capture is crucial for detailed chemical analysis.

Purpose of the Study:

• To demonstrate a combined SERS and STORM technique for super-resolution chemical imaging.
• To achieve high-resolution imaging of bacterial cells with simultaneous spectral data.
• To develop a versatile imaging method applicable to various biological samples and conditions.

Main Methods:

• Utilized ultra-thin silver substrates for SERS.
• Adapted STORM algorithms with a diffraction grating for spectral data acquisition.
• Imaged gram-positive and gram-negative bacteria.

Main Results:

• Achieved super-resolution imaging with spatial resolution <50 nm.
• Acquired spatially correlated SERS spectral content, differentiating cellular regions.
• Demonstrated excellent agreement with scanning electron microscopy images.
• Enabled imaging from below, suitable for thick specimens and turbid media.

Conclusions:

• The combined SERS-STORM technique provides high-resolution super-resolution chemical imaging.
• This method can identify unique chemical signatures of cells.
• The technique's ability to image through substrates and turbid liquids offers significant advantages for biological studies.