Fabrication of surface-enhanced Raman spectroscopy (SERS)-based biosensor using glancing angle deposition (GLAD) technique for the detection of E-coli bacteria

2021 ◽  
Author(s):  
Sathi Das ◽  
Dalip Singh Mehta ◽  
Kanchan Saxena
RSC Advances ◽  
2016 ◽  
Vol 6 (51) ◽  
pp. 45120-45126 ◽  
Author(s):  
Samir Kumar ◽  
Devesh K. Lodhi ◽  
J. P. Singh

We report a facile method to fabricate novel and recyclable Ag nanoparticle decorated TiO2 nanorod array substrates using a glancing angle deposition (GLAD) technique for photocatalysis and surface enhanced Raman scattering (SERS) applications.


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.


2005 ◽  
Vol 59 (10) ◽  
pp. 1222-1228 ◽  
Author(s):  
Mary L. Laucks ◽  
Atanu Sengupta ◽  
Karen Junge ◽  
E. James Davis ◽  
Brian D. Swanson

Psychro-active bacteria, important constituents of polar ecosystems, have a unique ability to remain active at temperatures below 0 °C, yet it is not known to what extent the composition of their outer cell surfaces aids in their low-temperature viability. In this study, aqueous suspensions of five strains of Arctic psychro-active marine bacteria (PAMB) (mostly sea-ice isolates), were characterized by surface-enhanced Raman spectroscopy (SERS) and compared with SERS spectra from E. coli and P. aerigunosa. We find the SERS spectra of the five psychro-active bacterial strains are similar within experimental reproducibility. However, these spectra are significantly different from the spectra of P. aeruginosa and E. coli. We find that the relative intensities of many of the common peaks show the largest differences reported so far for bacterial samples. An indication of a peak was found in the PAMB spectra that has been identified as characteristic of unsaturated fatty acids and suggests that the outer membranes of the PAMB may contain unsaturated fatty acids. We find that using suspensions of silver colloid particles greatly intensifies the Raman peaks and quenches the fluorescence from bacterial samples. This technique is useful for examination of specific biochemical differences among bacteria.


Author(s):  
Saba Bashir ◽  
Haq Nawaz ◽  
Muhammad Irfan Majeed ◽  
Mashkoor Mohsin ◽  
Ali Nawaz ◽  
...  

2007 ◽  
Vol 61 (7) ◽  
pp. 679-685 ◽  
Author(s):  
Lindsay J. Goeller ◽  
Mark R. Riley

Detection of pathogenic organisms in the environment presents several challenges due to the high cost and long times typically required for identification and quantification. Polymerase chain reaction (PCR) based methods are often hindered by the presence of polymerase inhibiting compounds and so direct methods of quantification that do not require enrichment or amplification are being sought. This work presents an analysis of pathogen detection using Raman spectroscopy to identify and quantify microorganisms without drying. Confocal Raman measurements of the bacterium Escherichia coli and of two bacteriophages, MS2 and PRD1, were analyzed for characteristic peaks and to estimate detection limits using traditional Raman and surface-enhanced Raman spectroscopy (SERS). MS2, PRD1, and E. coli produced differentiable Raman spectra with approximate detection limits for PRD1 and E. coli of 109 pfu/mL and 106 cells/mL, respectively. These high detection concentration limits are partly due to the small sampling volume of the confocal system but translate to quantification of as little as 100 bacteriophages to generate a reliable spectral signal. SERS increased signal intensity 103 fold and presented peaks that were visible using 2-second acquisitions; however, peak locations and intensities were variable, as typical with SERS. These results demonstrate that Raman spectroscopy and SERS have potential as a pathogen monitoring platform.


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