A novel particle-in-well technology for single-molecule sequencing by surface-enhanced Raman spectroscopy

TL;DR

This paper introduces a particle-in-well platform that stabilizes a gold nanoparticle for continuous, single-molecule Raman spectroscopy detection of nucleic acids, advancing DNA sequencing capabilities.

Contribution

The study presents a novel trapping method using a gold nanowell to enhance stability and sensitivity in single-molecule Raman spectroscopy for DNA sequencing.

Findings

Achieved stable trapping of a gold nanoparticle in a nanowell.

Enabled continuous detection of single molecules in liquid.

Validated hotspot size and molecule distance through spectral analysis.

Abstract

Single-molecule surface-enhanced Raman spectroscopy based on a particle trapped in a plasmonic nanopores provides a unique method for continued and controlled detection of peptide and DNA oligonucleotides in liquid medium. However, the Brownian motion of the particle and the molecule diffusion acting on the particle hinder single-molecule sequencing. In this study, we developed a method for trapping a gold nanoparticle in an air-filled gold nanowell (particle-in-well) to stabilize the particle and provide a powerful platform for continuous single molecule readout. The unlimited resident time of the particle-in-well device with single-molecule level sensitivity elevates nucleobase detection to a new level. We present a technique capable of detecting and monitoring solid-phase molecule diffusion within the plasmonic hotspot. Furthermore, the measured spectra were employed as input data for the validation of the plasmonic hotspot size and, consequently, the distance between the particle and the well. The obtained results form the statistical and experimental base for molecular translocation and DNA sequencing technologies.