Gold nanostar substrates for SERS-based chemical sensing in the femtomolar regime

Nanoscale ◽  
2014 ◽  
Vol 6 (15) ◽  
pp. 8891-8899 ◽  
Author(s):  
A. S. D. S. Indrasekara ◽  
S. Meyers ◽  
S. Shubeita ◽  
L. C. Feldman ◽  
T. Gustafsson ◽  
...  
Keyword(s):  
Detection Limit ◽  
Enhancement Factor ◽  
Chemical Sensing ◽  
Gold Nanostars ◽  
Sers Enhancement ◽  
Gold Nanostar

A SERS sensor based on gold nanostars is described. The size and sharpness of the nanostar spikes are tuned to maximize sensitivity and SERS enhancement, yielding a detection limit of 10−15 M and an enhancement factor of 109. The effectiveness of the sensor is proven for both chemisorbed and physisorbed analytes under non-resonant conditions and its multiplexing capability is demonstrated.

scholarly journals Optimizing the SERS enhancement of a facile gold nanostar immobilized paper-based SERS substrate

RSC Advances ◽  
2017 ◽  
Vol 7 (27) ◽  
pp. 16264-16272 ◽  
Author(s):  
Shuai He ◽  
Jefri Chua ◽  
Eddie Khay Ming Tan ◽  
James Chen Yong Kah
Keyword(s):  
Enhancement Factor ◽  
Low Cost ◽  
Sers Substrate ◽  
Sers Enhancement ◽  
Gold Nanostar

Schematic of study to optimize the SERS enhancement factor of a low cost and facile gold nanostar (AuNS)-based paper-SERS substrate through optimizing the paper materials, immobilization strategies, and SERS acquisition conditions.

Validation of SERS enhancement factor measurements

2017 ◽  
Vol 49 (3) ◽  
pp. 462-471 ◽  
Author(s):  
R. Pilot ◽  
R. Bozio
Keyword(s):  
Enhancement Factor ◽  
Sers Enhancement

Gold nanostars as SERS-active substrates for FT-Raman spectroscopy

RSC Advances ◽  
2015 ◽  
Vol 5 (11) ◽  
pp. 8523-8532 ◽  
Author(s):  
Angela Zoppi ◽  
Silvana Trigari ◽  
Giancarlo Margheri ◽  
Maurizio Muniz-Miranda ◽  
Emilia Giorgetti
Keyword(s):  
Raman Spectroscopy ◽  
Enhancement Factor ◽  
Limit Of Detection ◽  
Gold Nanostars ◽  
Raman Enhancement ◽  
Ft Raman Spectroscopy ◽  
Ft Raman

Surfactant-free and CTAB-stabilized gold nanostars were synthesized. Their FT-SERS activity was tested. A nanomolar limit of detection and a Raman enhancement factor of more than 105 were found.

scholarly journals Optimization of the particle density to maximize the SERS enhancement factor of periodic plasmonic nanostructure array

2016 ◽  
Vol 24 (18) ◽  
pp. 20613 ◽  
Author(s):  
Shuhua Wei ◽  
Mengjie Zheng ◽  
Quan Xiang ◽  
Hailong Hu ◽  
Huigao Duan
Keyword(s):  
Enhancement Factor ◽  
Particle Density ◽  
Sers Enhancement ◽  
Plasmonic Nanostructure ◽  
Nanostructure Array

Robust SERS Enhancement Factor Statistics Using Rotational Correlation Spectroscopy

Nano Letters ◽  
2012 ◽  
Vol 12 (6) ◽  
pp. 2912-2917 ◽  
Author(s):  
Ted A. Laurence ◽  
Gary B. Braun ◽  
Norbert O. Reich ◽  
Martin Moskovits
Keyword(s):  
Enhancement Factor ◽  
Correlation Spectroscopy ◽  
Sers Enhancement ◽  
Rotational Correlation

Corrigendum to “Electrochemical pathway for the quantification of SERS enhancement factor” [Electrochem. Commun. 49 (2014) 103–106]

2015 ◽  
Vol 52 ◽  
pp. 89
Author(s):  
Arumugam Sivanesan ◽  
Witold Adamkiewicz ◽  
Govindasamy Kalaivani ◽  
Agnieszka Kamińska ◽  
Jacek Waluk ◽  
...  
Keyword(s):  
Enhancement Factor ◽  
Sers Enhancement

Enhanced Raman scattering from aromatic dithiols electrosprayed into plasmonic nanojunctions

2015 ◽  
Vol 184 ◽  
pp. 339-357 ◽  
Author(s):  
Patrick Z. El-Khoury ◽  
Grant E. Johnson ◽  
Irina V. Novikova ◽  
Yu Gong ◽  
Alan G. Joly ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Single Molecule ◽  
Molecular Orientation ◽  
Enhancement Factor ◽  
Surface Enhanced Raman Spectroscopy ◽  
Vibrational States ◽  
Vibrational Dephasing ◽  
Sers Enhancement ◽  
Silver Nanospheres ◽  
2D Array

We describe surface enhanced Raman spectroscopy (SERS) experiments in which molecular coverage is systematically varied from 3.8 × 105 to 3.8 × 102 to 0.38 molecules per μm2 using electrospray deposition of ethanolic 4,4′-dimercaptostilbene (DMS) solutions. The plasmonic SERS substrate used herein consists of a well-characterized 2-dimensional (2D) array of silver nanospheres (see El-Khoury et al., J. Chem. Phys., 2014, 141, 214308), previously shown to feature uniform topography and plasmonic response, as well as intense SERS activity. When compared to their ensemble averaged analogues, the spatially and temporally averaged spectra of a single molecule exhibit several unique features including: (i) distinct relative intensities of the observable Raman-active vibrational states, (ii) more pronounced SERS backgrounds, and (iii) broader Raman lines indicative of faster vibrational dephasing. The first observation may be understood on the basis of an intuitive physical picture in which the removal of averaging over multiple molecules exposes the tensorial nature of Raman scattering. When an oriented single molecule gives rise to the recorded SERS spectra, the relative orientation of the molecule with respect to vector components of the local electric field determines the relative intensities of the observable vibrational states. Using a single molecule SERS framework, described herein, we derive a unique molecular orientation in which a single DMS molecule is isolated at a nanojunction formed between two silver nanospheres in the 2D array. The DMS molecule is found lying nearly flat with respect to the metal. The derived orientation of a single molecule at a plasmonic nanojunction is consistent with observations (ii) and (iii). In particular, a careful inspection of the temporal spectral variations along the recorded single molecule SERS time sequences reveals that the time-averaged SERS backgrounds arise from individual molecular events, marked by broadened SERS signatures. We assign the broadened spectra along the SERS time sequence – which sum up to a SERS background in the averaged spectra – to instances in which the π-framework of the DMS molecule is parallel to the metal at a classical plasmonic nanojunction. This also accounts for Raman line broadening as a result of fast vibrational dephasing, and driven by molecular reorientation at a plasmonic nanojunction. Furthermore, we report on the molecular orientation dependence of single molecule SERS enhancement factors. We find that in the case of a single DMS molecule isolated at a plasmonic nanojunction, molecular orientation may affect the derived single molecule SERS enhancement factor by up to 5 orders of magnitude. Taking both chemical effects as well as molecular orientation into account, we were able to estimate a single molecule enhancement factor of ∼1010 in our measurements.

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