Raman spectra of deuterated hydrocarbons for labeling applications

Abstract

Raman spectroscopy is used for studying the composition of cell lipidome. However, the Raman approach suffers from limited distinguish power for different lipids. In recent years, isotopically labeled molecules are increasingly used to enhance the Raman resolution of similar compounds in biological samples. Here, we present Raman study of fully deuterated stearic acid (stearic‐d35), semi‐deuterated oleic acid (oleic d‐9), arachidonic acid with deuterated methine groups (arachidonic‐d8), and their hydrogenated analogs. Polarization properties and temperature dependences of CD stretching modes were investigated to reveal the capability of the isotopically shifted Raman peaks in molecular characterization. Sensitivity of Raman peaks to order–disorder transition corresponding was demonstrated for deuterated methine, methylene, and methyl groups. It was found that the isotopically shifted Raman peaks provide information about the orientation of deuterated Raman tags and their surroundings.

Mechanism of Plasmon-Induced Catalysis of Thiolates and the Impact of Reaction Conditions

“…2000–3000 cm –1 . 33 − 35 It is also noteworthy that no deuterium-related signal (except for D 2 O bumps) was detected in the Raman-silent region (ca. 1800–2800 cm –1 ) in any NTP and ATP sample ( Figure S7 ).…”

Spatial sterol metabolism unveiled by stimulated Raman imaging

“…To demonstrate the chemical specificity of our system, a mathematical model was built to quantify and search for an optimal signal-to-background ratio (SBR, see Supplementary Figure S4 ). The Raman peak width of common small-molecule metabolites is about 25–40 cm -1 , such as glucose (42 cm -1 at 1,373 cm -1 ) ( Söderholm et al, 1999 ), ergosterol (38 cm -1 at 2,870 cm -1 ), and deuterated lipids (∼20 cm -1 at 2,103 cm -1 ) ( Argov et al, 2008 ; Fu et al, 2013 ; Zhang et al, 2013 ; Zhang et al, 2013 ; Huang et al, 2020 ; Chen et al, 2021 ; Okotrub et al, 2022 ). The resulting SBR targeting ergosterol indicated high selectivity by <20 cm −1 narrowband excitations ( Supplementary Figure S4D ).…”