Bacterial DNA Recognition by SERS Active Plasma-Coupled Nanogold.
Vasyl ShvalyaAswathy VasudevanMartina ModicMohammad AbutoamaCene SkubicNejc NadižarJanez ZavašnikDamjan VengustAleksander ZidanšekIbrahim AbdulhalimDamjana RozmanUroš CvelbarPublished in: Nano letters (2022)
It is shown that surface-enhanced Raman spectroscopy (SERS) can identify bacteria based on their genomic DNA composition, acting as a "sample-distinguishing marker". Successful spectral differentiation of bacterial species was accomplished with nanogold aggregates synthesized through single-step plasma reduction of the ionic gold-containing vapored precursor. A high enhancement factor (EF = 10 7 ) in truncated coupled plasmonic particulates allowed SERS-probing at nanogram sample quantities. Simulations confirmed the occurrence of the strongest electric field confinement within nanometric gaps between gold dimers/chains from where the molecular fingerprints of bacterial DNA fragments gained photon scattering enhancement. The most prominent Raman modes linked to fundamental base-pair molecular vibrations were deconvoluted and used to proceed with nitrogenous base content estimation. The genomic composition (percentage of guanine-cytosine and adenine-thymine) was successfully validated by third-generation sequencing using nanopore technology, further proving that the SERS technique can be employed to swiftly specify bioentities by the discriminative principal-component statistical approach.
Keyphrases
- raman spectroscopy
- single molecule
- living cells
- circulating tumor
- gold nanoparticles
- cell free
- sensitive detection
- copy number
- monte carlo
- label free
- molecular dynamics
- nucleic acid
- gene expression
- magnetic resonance imaging
- circulating tumor cells
- silver nanoparticles
- single cell
- quantum dots
- genome wide
- computed tomography