Tip-Enhanced Raman Nanospectroscopy of Smooth Spherical Gold Nanoparticles.
Ashish BhattaraiZhihua ChengAlan G JolyIrina V NovikovaJames E EvansZachary D SchultzMatthew R JonesPatrick Z El-KhouryPublished in: The journal of physical chemistry letters (2020)
We record nanoscale-resolved chemical images of thiobenzonitrile (TBN)-functionalized smooth gold nanospheres on silicon via tip-enhanced Raman (TER) nanospectroscopy. The recorded images trace the nascence of the familiar doughnut-shaped scattering profile of nanoparticles on silicon at its origin (the particle surface), which appears as a horseshoe-shaped scattering pattern under our experimental conditions. The local optical field maps are in agreement with their simulated finite-difference time-domain analogues. Analysis of the recorded spectra with the aid of ab-initio-molecular-dynamics-based Raman spectral simulations further suggests that optical rectification and molecular charging take place throughout the course of atomic-force-microscopy-based TER nanoscale chemical imaging.
Keyphrases
- atomic force microscopy
- molecular dynamics
- high speed
- high resolution
- density functional theory
- gold nanoparticles
- optical coherence tomography
- single molecule
- deep learning
- convolutional neural network
- raman spectroscopy
- label free
- monte carlo
- molecular docking
- quantum dots
- heavy metals
- machine learning
- magnetic resonance imaging
- computed tomography
- molecularly imprinted
- photodynamic therapy
- fluorescence imaging
- walled carbon nanotubes