SERS detection of biomolecules using lithographed nanoparticles towards a reproducible SERS biosensor

Abstract

In this paper we highlight the accurate spectral detection of bovine serum albumin and ribonuclease-A using a surface-enhanced Raman scattering (SERS) substrate based on gold nanocylinders obtained by electron-beam lithography (EBL). The nanocylinders have diameters from 100 to 180 nm with a gap of 200 nm. We demonstrate that optimizing the size and the shape of the lithographed gold nanocylinders, we can obtain SERS spectra of proteins at low concentration. This SERS study enabled us to estimate high enhancement factors (10(5) for BSA and 10(7) for RNase-A) of important bands in the protein Raman spectrum measured for 1 mM concentration. We demonstrate that, to reach the highest enhancement, it is necessary to optimize the SERS signal and that the main parameter of optimization is the LSPR position. The LSPR have to be suitably located between the laser excitation wavelength, which is 632.8 nm, and the position of the considered Raman band. Our study underlines the efficiency of gold nanocylinder arrays in the spectral detection of proteins.

SERS-active metal-dielectric nanostructures integrated in microfluidic devices for label-free quantitative detection of miRNA

“…In particular, the ring breathing modes (adenine at 730 cm (aromatic amino acids) is reduced. 41 These observations are in agreement with the occurred immobilization of the probe on the surface, which displaces the protein. Moreover, a certain surface saturation is observed for concentrations higher than 25 µM.…”

The Effect of Dielectric Constants on Noble Metal/Semiconductor SERS Enhancement: FDTD Simulation and Experiment Validation of Ag/Ge and Ag/Si Substrates

“…Over the past several decades, many techniques have been developed for fabricating the high-performance SERS-active substrates, such as electron beam lithography5, Langmuir-Blodgett assembly6, nanosphere lithography7, self-assembly8, DNA-assisted9, and oblique angle deposition10. All these methods were valuable.…”

Plasmon based biosensor for distinguishing different peptides mutation states

“…The graph shows the spectral difference between wild type and mutated peptide. In particular, the positive difference values for the band centered at around 1549 and 1402 cm −1 are related to the ring breathing vibration and aromatic CH x bending vibration (wild type)293445 and the negative values for the band centered at 1350 and 1645 cm −1 are attributed to the δN–H and combined vibrational of νC = O and δC–H x (mutated), respectively. Furthermore, the wild type peptide expresses the aromatic benzene ring related vibration, whereas the mutated peptide shows an excess N–H and aliphatic C–H x from arginine amino acid.…”

“…1). The present nanostructures, characterized by well-defined corners, were chosen to spatially define and control the local electric field distribution, hence to improve the SERS performance with respect to nanosphere based structures113334.…”