Chiral Gold Staining Enables In Situ Plasmonic Engineering for Single-Bacterium Microscopic Imaging Analysis

Area of Science:

• Materials Science
• Nanotechnology
• Biotechnology

Background:

• Geometric chirality in nanomaterials arises from molecular asymmetry.
• Existing methods for creating chiral nanostructures are complex.

Purpose of the Study:

• To develop a universal strategy for fabricating in situ-synthesized gold nanostructures (issAu) on biological substrates.
• To engineer chiral issAu onto bacteria for novel nanomaterials and imaging applications.

Main Methods:

• A staining solution containing gold precursors, surfactant, and reductant was used for in situ synthesis.
• Exogenous cysteine enantiomers were introduced to induce anisotropic growth and plasmonic chirality.
• The method was applied to bacterial systems for oriented nanostructure growth.

Main Results:

• Successfully fabricated oriented issAu on bacterial skeletons.
• Demonstrated the role of cysteine enantiomers in anisotropic growth and chiral evolution.
• Engineered chiral issAu onto bacteria, creating versatile bacterium-derived nanomaterials.
• Enabled in situ plasmonic engineering of pathogenic bacteria for optical microscopy imaging.

Conclusions:

• The developed staining method provides a facile approach for chiral nanoengineering of biological entities.
• This protocol facilitates in situ plasmonic engineering of bacteria for microbial imaging.
• The resulting nanobioheterostructures hold significant potential in antimicrobial and bioanalytical applications.