TY - JOUR
T1 - Membrane surface-enhanced Raman spectroscopy for sensitive detection of molecular behavior of lipid assemblies
AU - Suga, Keishi
AU - Yoshida, Tomohiro
AU - Ishii, Haruyuki
AU - Okamoto, Yukihiro
AU - Nagao, Daisuke
AU - Konno, Mikio
AU - Umakoshi, Hiroshi
N1 - Publisher Copyright:
© 2015 American Chemical Society.
PY - 2015/5/5
Y1 - 2015/5/5
N2 - The dynamic properties of phospholipid (PL) membranes (phase state and phase transition) play crucial roles in biological systems. However, highly sensitive, direct analytical methods that shed light on the nature of lipids and their assemblies have not been developed to date. Here, we describe the analysis of PL-modified Au nanoparticles (Au@PL) using membrane surface-enhanced Raman spectroscopy (MSERS) and report the properties of the self-assembled PL membranes on the Au nanoparticle. The Raman intensity per PL concentration increased by 50-170 times with Au@PL, as compared to large unilamellar vesicles (LUVs) at the same PL concentration. The phase state and phase transition temperature of the PL membrane of Au@PL were investigated by analyzing the Raman peak ratio (R = I2882/I2930). The enhancement at 714 cm-1 (EF(714)) varied with the hydrocarbon chain length of the PLs and the assembled degree of Au@PLs. In calculation, the EF(714),assembled was estimated to be 111-142 when the distance between AuNPs was 7.0-7.5 nm, which was correlated to the speculative enhancement factor, suggesting that the assembly of the Au@PLs contributed to the MSERS.
AB - The dynamic properties of phospholipid (PL) membranes (phase state and phase transition) play crucial roles in biological systems. However, highly sensitive, direct analytical methods that shed light on the nature of lipids and their assemblies have not been developed to date. Here, we describe the analysis of PL-modified Au nanoparticles (Au@PL) using membrane surface-enhanced Raman spectroscopy (MSERS) and report the properties of the self-assembled PL membranes on the Au nanoparticle. The Raman intensity per PL concentration increased by 50-170 times with Au@PL, as compared to large unilamellar vesicles (LUVs) at the same PL concentration. The phase state and phase transition temperature of the PL membrane of Au@PL were investigated by analyzing the Raman peak ratio (R = I2882/I2930). The enhancement at 714 cm-1 (EF(714)) varied with the hydrocarbon chain length of the PLs and the assembled degree of Au@PLs. In calculation, the EF(714),assembled was estimated to be 111-142 when the distance between AuNPs was 7.0-7.5 nm, which was correlated to the speculative enhancement factor, suggesting that the assembly of the Au@PLs contributed to the MSERS.
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U2 - 10.1021/ac5048532
DO - 10.1021/ac5048532
M3 - Article
C2 - 25839320
AN - SCOPUS:84928966611
SN - 0003-2700
VL - 87
SP - 4772
EP - 4780
JO - Analytical Chemistry
JF - Analytical Chemistry
IS - 9
ER -