Bacterial DNA Recognition by SERS Active Plasma-Coupled Nanogold

Abstract

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 = 107) 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.

Adjunctive Testing Using Biospectral Emission Sequencing: Bioregulatory Intelligence Technology in Parallel With the Goals of Artificial Intelligence in Medicine

“…Similar technologies to BES are being used in laboratory settings, such as conventional UV-resonance Raman sequence analysis, which is used for the detection and differentiation of microbial types and strains in medical microbial testing, and even in mixed background materials such as soil and food [ 25 ]. For example, Raman spectroscopic photonic analysis is used for the rapid identification of microorganisms based on their unique coherent molecular and DNA emissions [ 26 ]. These emissions are enhanced by the liquid-crystalline matrix found in living systems.…”

Simultaneous Protein Colorful Imaging via Raman Signal Classification

“…Detecting proteins is important for understanding life sciences, diagnosing diseases, and developing pharmaceuticals. − Raman spectroscopy is especially used for detecting or quantifying molecules cause it is a label-free method that provides distinctive molecular information known as a “molecular fingerprint. − So, it is notably effective in identifying biomolecules, including proteins, DNA, and extracellular vesicles, for disease diagnosis and treatment monitoring. ,− Despite this, the general Raman signal-based protein imaging or quantification uses the Raman labels, known as Raman dye, to detect the target being measured, impeding the advantages of label-free Raman signal measurement techniques. ,− This method encounters difficulties quantifying numerous proteins due to its reliance on distinct Raman peaks, a complexity exacerbated by the comparable compositions of biomolecules. − Consequently, numerous studies have endeavored to tackle this matter by utilizing various colored Raman labels or statistical methodologies. − …”