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

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.

2017 ◽  
Author(s):  
Masao Gen ◽  
Chak K. Chan

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.


2013 ◽  
Vol 15 (12) ◽  
pp. 4130 ◽  
Author(s):  
Hai-Xin Lin ◽  
Jie-Ming Li ◽  
Bi-Ju Liu ◽  
De-Yu Liu ◽  
Jinxuan Liu ◽  
...  

2019 ◽  
Vol 6 (9) ◽  
pp. 2318-2324 ◽  
Author(s):  
Mansha Gao ◽  
Peng Miao ◽  
Xijiang Han ◽  
Cheng Sun ◽  
Yan Ma ◽  
...  

Single M(OH)x (M = Fe, Co, Ni) hollow octahedral microcage particles are explored as novel SERS-active substrates for sensitive dye molecule detection.


2019 ◽  
Vol 74 (3) ◽  
pp. 295-304
Author(s):  
Cecilia Baraldi ◽  
Maria Pamela Toti ◽  
Elsa Van Elslande ◽  
Philippe Walter ◽  
Maria Cristina Gamberini

Little is known concerning Phoenician and Punic cosmetics, and pertinent studies and analyses on archaeological finds are particularly scanty. The present study has taken into account 22 archaeological red and pink Punic make-up samples collected in several Sicilian museums. The samples were analyzed by infrared spectroscopy, Raman microscopy, and surface-enhanced Raman spectroscopy (SERS). The analyses revealed an interesting and unusual variability in the use of raw materials, ranging from the mineral to the organic world. Not only traditional dye-based pigments were identified, but also rare ones never reported previously for this use. We show also an occurrence unusual in antiquity of a lead chromate block presumably intended to be ground just before its use in cosmetics.


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