A Simple Approach to Engineer SERS Substrates and Plasmonic Thin Film

Abstract

Solid supported 2D assembly of silver nanocubes was fabricated by Langmuir-Blodgett technique and employed to investigate its surface enhanced Raman scattering (SERS) and surface enhance fluorescence (SEF) activities by detecting Rh6G in solution of varied concentrations, that is, 10−12 M, 10−9 M, 10−6 M, and 10−3 M. SERS was detected from a nanomolar concentration of Rh6G whereas SEF was detected from a picomolar concentration. Further, the substrate was subjected to thermal annealing to fabricate plasmonic thin film. The formation of thin film was followed by monitoring its surface plasmon resonance spectra and atomic force microscopic images. It was observed that the characteristic spectral peaks of silver nanocubes merged into a broad spectral band as the annealing time was increased and the intensity of the band decreased with the formation of thin film. The obtained result implies that thermal annealing could be a simple approach to create nanoscale gaps in SERS substrate and to engineer continuous thin film from the assembly of discrete nanoparticles.

Reflective FT‐NIR and SERS studies of HER‐II breast cancer biomarker using plasmonic‐active nanostructured thin film immobilized oriented antibody

“…SERS has been used to study protein binding orientation [57], characterize protein activity [64] and detect molecules based on their Raman fingerprint in biosensor applications [65]. In this work, although the gold chip surface is optically smooth, the nanoscale interparticle gaps between the deposited gold nanoparticles serve as a factor of enhancement for SERS [66]. As a complementary technique to FT-NIR spectroscopy, SERS was used to (a) investigate the surface chemistry of the gold chip biosensor during its fabrication and (b) confirm the BC biomarker binding to the functionalized surface of the biosensor.…”

Annealing effect of gold thin films on the light output performances of organic light emitting diodes

“…Morphological and optical linear/nonlinear properties were investigated, before and after annealing, as a function of the film thickness. In the work by Ahamad, thin films were deposited using the Langmuir-Blodgett technique and atomic force microscopy (AFM) topographic images of the silver nanocube monolayer were recorded at different annealing times [40]. Ahn et al transformed the ultrathin electroluminescent film coated on the fused quartz surface to NPs via annealing at 250 • C [41].…”