Surface enhanced Raman spectroscopy of unilamellar liposomes loaded with silver nanoparticles
Date
2017Source Title
Journal of Nanoscience and Nanotechnology
Print ISSN
1533-4880
Electronic ISSN
1533-4899
Publisher
American Scientific Publishers
Volume
17
Issue
12
Pages
8894 - 8900
Language
English
Type
ArticleItem Usage Stats
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Abstract
Imaging organic molecules using surface-enhanced Raman spectroscopy (SERS) has drawn attention due to its non-invasive nature and label-free approach. The SERS approach can be used in tracking organic molecules and monitoring unique Raman spectra of the organic molecules bound to metal nanoparticles (NPs). We prepared unilamellar liposomes composed of 1,2-dipalmitoylsn-glycero-3-phosphocholine (DPPC) molecules with a diameter of around 100 nm. Electrostatic binding of silver (Ag) NPs on the surface of the unilamellar liposomes was achieved by the reduction of silver nitrate (AgNO3) which produces SERS active silver colloidal particles on the unilamellar liposome surfaces. Highly enhanced electromagnetic fields localized around neighbouring Ag NPs provide hot-spot construction around the liposomes, due to the spatial distribution of SERS enhancement in the unilamellar liposomes. It was observed that the signals fluctuate on a second time scale, presumably due to conformational change of DPPC chain and local Brownian motion of liposomal spheres.