Tunable silver and gold substrates for surface enhanced raman spectroscopy

Author(s):  
Wayne Weimer ◽  
R. Gupta
2008 ◽  
Vol 62 (9) ◽  
pp. 992-1000 ◽  
Author(s):  
Ratna Tantra ◽  
Richard J. C. Brown ◽  
Martin J. T. Milton ◽  
Dipak Gohil

2020 ◽  
Vol 22 (28) ◽  
pp. 15953-15965
Author(s):  
Erik D. Emmons ◽  
Jason A. Guicheteau ◽  
Augustus W. Fountain ◽  
Ashish Tripathi

The effect of substituents on the surface adsorption equilibria on gold substrates was studied using surface-enhanced Raman spectroscopy in order to determine the effects of the localized dipole moments and charge donating/withdrawing properties on the binding affinity.


Nanomaterials ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 164 ◽  
Author(s):  
Dmitry E. Tatarkin ◽  
Dmitry I. Yakubovsky ◽  
Georgy A. Ermolaev ◽  
Yury V. Stebunov ◽  
Artem A. Voronov ◽  
...  

Graphene is a promising platform for surface-enhanced Raman spectroscopy (SERS)-active substrates, primarily due to the possibility of quenching photoluminescence and fluorescence. Here we study ultrathin gold films near the percolation threshold fabricated by electron-beam deposition on monolayer CVD graphene. The advantages of such hybrid graphene/gold substrates for surface-enhanced Raman spectroscopy are discussed in comparison with conventional substrates without the graphene layer. The percolation threshold is determined by independent measurements of the sheet resistance and effective dielectric constant by spectroscopic ellipsometry. The surface morphology of the ultrathin gold films is analyzed by the use of scanning electron microscopy (SEM) and atomic force microscopy (AFM), and the thicknesses of the films in addition to the quartz-crystal mass-thickness sensor are also measured by AFM. We experimentally demonstrate that the maximum SERS signal is observed near and slightly below the percolation threshold. In this case, the region of maximum enhancement of the SERS signal can be determined using the figure of merit (FOM), which is the ratio of the real and imaginary parts of the effective dielectric permittivity of the films. SERS measurements on hybrid graphene/gold substrates with the dye Crystal Violet show an enhancement factor of ~105 and also demonstrate the ability of graphene to quench photoluminescence by an average of ~60%.


2017 ◽  
Vol 4 (7) ◽  
pp. 075027 ◽  
Author(s):  
Astha Singh ◽  
Geeta Sharma ◽  
Neeraj Ranjan ◽  
Kshitij Mittholiya ◽  
Anuj Bhatnagar ◽  
...  

2021 ◽  
pp. 1-11
Author(s):  
Petar Asenov Atanasov ◽  
Nikolay Nedyalkov Nedyalkov ◽  
Naoki Fukata ◽  
Wipakorn Jevasuwan

2017 ◽  
Author(s):  
Caitlin S. DeJong ◽  
David I. Wang ◽  
Aleksandr Polyakov ◽  
Anita Rogacs ◽  
Steven J. Simske ◽  
...  

Through the direct detection of bacterial volatile organic compounds (VOCs), via surface enhanced Raman spectroscopy (SERS), we report here a reconfigurable assay for the identification and monitoring of bacteria. We demonstrate differentiation between highly clinically relevant organisms: <i>Escherichia coli</i>, <i>Enterobacter cloacae</i>, and <i>Serratia marcescens</i>. This is the first differentiation of bacteria via SERS of bacterial VOC signatures. The assay also detected as few as 10 CFU/ml of <i>E. coli</i> in under 12 hrs, and detected <i>E. coli</i> from whole human blood and human urine in 16 hrs at clinically relevant concentrations of 10<sup>3</sup> CFU/ml and 10<sup>4</sup> CFU/ml, respectively. In addition, the recent emergence of portable Raman spectrometers uniquely allows SERS to bring VOC detection to point-of-care settings for diagnosing bacterial infections.


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