scholarly journals Surface-enhanced Raman spectroscopy for chemical and biological sensing using nanoplasmonics: The relevance of interparticle spacing and surface morphology

2020 ◽  
Vol 7 (3) ◽  
pp. 031307
Author(s):  
Vasyl Shvalya ◽  
Gregor Filipič ◽  
Janez Zavašnik ◽  
Ibrahim Abdulhalim ◽  
Uroš Cvelbar
Keyword(s):  
Raman Spectroscopy ◽  
Surface Morphology ◽  
Surface Enhanced Raman Spectroscopy ◽  
Interparticle Spacing ◽  
Biological Sensing ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

scholarly journals In SituDetection of Trace Furfural in Aqueous Solution Based on Au Nanoparticle/Au Film Surface-Enhanced Raman Spectroscopy

2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Wei Qi ◽  
Weigen Chen ◽  
Fu Wan ◽  
Jingxin Zou ◽  
Zhaoliang Gu
Keyword(s):  
Raman Spectroscopy ◽  
Electric Field ◽  
Surface Enhanced Raman Spectroscopy ◽  
Interparticle Spacing ◽  
Au Nanoparticle ◽  
Fdtd Simulation ◽  
Au Film ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Simulation Results

Furfural is an important chemical solvent and intermediate. Sensitive detection of this compound has attracted great interest in various fields. Surface-enhanced Raman spectroscopy (SERS) is a highly sensitive method for material detection because of its optical enhancement effect of plasmonic nanostructures. This study presents a simple and versatile method to synthesize a SERS substrate, where polyaminothiophenol (PATP) was used to realize the stable combination of Au nanoparticles (AuNPs) and Au film via self-assembly. The near-field electric field distribution was calculated using the finite difference time domain (FDTD) simulation to determine the parameters responsible for electric field enhancement. The simulation results show that SERS enhanced factors are sensitive to interparticle spacing and materials for solid support but insensitive to particle size. Moreover, the experimental results show that the optimized substrates with the highest Raman activity were formed by six layers of 60 nm AuNPs decorated on a 30 nm thick Au film, thereby validating the simulation results. The SERS factor of the optimal substrates is approximately 5.57 × 103, and thein situdetection limit is 4.8 ppm. The 3D Raman spectra, relative standard deviation values for major peaks, and changes in signal intensity with time show the good reproducibility and stability of the substrates.

Bacterial detection and differentiation via direct volatile organic compound sensing with surface enhanced Raman spectroscopy

2017 ◽  
Author(s):  
Caitlin S. DeJong ◽  
David I. Wang ◽  
Aleksandr Polyakov ◽  
Anita Rogacs ◽  
Steven J. Simske ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Bacterial Infections ◽  
Direct Detection ◽  
Point Of Care ◽  
Surface Enhanced Raman Spectroscopy ◽  
E Coli ◽  
Recent Emergence ◽  
Surface Enhanced ◽  
Volatile Organic ◽  
Surface Enhanced Raman

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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