Reliable Solid Organic Matter Thermal Maturity Assessment Using Surface Enhanced Raman Spectroscopy and Case Studies

2018 ◽  
Author(s):  
Raymond Jiang ◽  
Li Gao ◽  
Andrew Bishop ◽  
Yongchun Tang
Keyword(s):  
Raman Spectroscopy ◽  
Organic Matter ◽  
Case Studies ◽  
Surface Enhanced Raman Spectroscopy ◽  
Thermal Maturity ◽  
Maturity Assessment ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

scholarly journals Electrospray-Surface Enhanced Raman Spectroscopy (ES-SERS) for probing surface chemical compositions of atmospherically relevant particles

2017 ◽  
Author(s):  
Masao Gen ◽  
Chak K. Chan
Keyword(s):  
Raman Spectroscopy ◽  
Organic Matter ◽  
Particle Surface ◽  
Adsorbed Water ◽  
Surface Enhanced Raman Spectroscopy ◽  
Chemical Compositions ◽  
Surface Chemical ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Atmospherically Relevant

Abstract. We present electrospray-surface enhanced Raman spectroscopy (ES-SERS) as a new approach to measuring the surface chemical compositions of atmospherically relevant particles. The surface-sensitive SERS is realized by electrospraying Ag nanoparticle aerosols over analyte particles. Spectral features at v(SO42−), v(C-H) and v(O-H) modes were observed from the normal Raman and SERS measurements of laboratory-generated supermicron particles of ammonium sulfate (AS), AS mixed with succinic acid (AS/SA) and AS mixed with sucrose (AS/sucrose). SERS measurements showed strong interaction (or chemisorption) between Ag nanoparticles and surface aqueous sulfate [SO42−] with [SO42−]AS/sucrose > [SO42−]AS/SA > [SO42−]AS. Enhanced spectra of the solid AS and AS/SA particles revealed the formation of surface-adsorbed water on their surfaces at 60 % relative humidity. These observations of surface aqueous sulfate and adsorbed water demonstrate a possible role of surface-adsorbed water in facilitating the dissolution of sulfate from the bulk phase into its water layer(s). Submicron ambient aerosol particles collected in Hong Kong exhibited non-enhanced features of black carbon and enhanced features of sulfate and organic matter (carbonyl group), indicating an enrichment of sulfate and organic matter on the particle surface.

scholarly journals Electrospray surface-enhanced Raman spectroscopy (ES-SERS) for probing surface chemical compositions of atmospherically relevant particles

2017 ◽  
Vol 17 (22) ◽  
pp. 14025-14037 ◽  
Author(s):  
Masao Gen ◽  
Chak K. Chan
Keyword(s):  
Raman Spectroscopy ◽  
Organic Matter ◽  
Particle Surface ◽  
Adsorbed Water ◽  
Surface Enhanced Raman Spectroscopy ◽  
Chemical Compositions ◽  
Surface Chemical ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Atmospherically Relevant

Abstract. We present electrospray surface-enhanced Raman spectroscopy (ES-SERS) as a new approach to measuring the surface chemical compositions of atmospherically relevant particles. The surface-sensitive SERS is realized by electrospraying Ag nanoparticle aerosols over analyte particles. Spectral features at v(SO42−), v(C–H) and v(O–H) modes were observed from the normal Raman and SERS measurements of laboratory-generated supermicron particles of ammonium sulfate (AS), AS mixed with succinic acid (AS ∕ SA) and AS mixed with sucrose (AS ∕ sucrose). SERS measurements showed strong interaction (or chemisorption) between Ag nanoparticles and surface aqueous sulfate [SO42−] with [SO42−]AS ∕ sucrose  >  [SO42−]AS ∕ SA  >  [SO42−]AS. Enhanced spectra of the solid AS and AS ∕ SA particles revealed the formation of surface-adsorbed water on their surfaces at 60 % relative humidity. These observations of surface aqueous sulfate and adsorbed water demonstrate a possible role of surface-adsorbed water in facilitating the dissolution of sulfate from the bulk phase into its water layer(s). Submicron ambient aerosol particles collected in Hong Kong exhibited non-enhanced features of black carbon and enhanced features of sulfate and organic matter (carbonyl group), indicating an enrichment of sulfate and organic matter on the particle surface.

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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