title: Clean substrates prepared by chemical adsorption of iodide followed by electrochemical oxidation for surface-enhanced Raman spectroscopic study of cell membrane.
abstract: Surface-enhanced Raman spectroscopy (SERS) has received renewed interest in recent years in fields such as trace analysis, biorelated diagnosis, and living cell study. However, the interference of impurities left on the surface from the preparation process of substrates or adsorbed from the ambient environment limits to some extent the application of SERS for analysis of trace or unknown samples. In the present paper, we propose a method to prepare clean SERS substrates by a combined method of chemical adsorption of iodide on the Au surface to remove the surface impurities and electrochemical oxidation of the adsorbed iodide to obtain a clean and impurity-free surface for SERS measurement. Time-dependent control experiment of untreated and treated substrate reveals that this method is very effective in obtaining substrates free of impurities. SERS mapping demonstrates the SERS activity of the substrate is homogeneous over the whole surface. The obtained clean substrate enables us to study the structures of the cell membrane with SERS and even to perform SERS mapping to visualize the distribution of amino acids over the membrane of a living cell.
authors.affiliation: State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, 361005 Xiamen, China.
authors.forename: Ming-De
authors.initials: MD
authors.lastname: Li
authors.forename: Yan
authors.initials: Y
authors.lastname: Cui
authors.forename: Min-Xia
authors.initials: MX
authors.lastname: Gao
authors.forename: Jia
authors.initials: J
authors.lastname: Luo
authors.forename: Bin
authors.initials: B
authors.lastname: Ren
authors.forename: Zhong-Qun
authors.initials: ZQ
authors.lastname: Tian
mesh_terms: D000327:Adsorption; D000818:Animals; D002462:Cell Membrane / Q000737:chemistry*; D002478:Cells, Cultured; D006224:Cricetinae; D003412:Cricetulus; D004563:Electrochemistry / Q000379:methods*; D005347:Fibroblasts / Q000166:cytology; D006046:Gold / Q000737:chemistry*; D008168:Lung / Q000166:cytology; D008565:Membrane Proteins / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D010084:Oxidation-Reduction; D011193:Potassium Iodide / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013499:Surface Properties; D017971:Tin Compounds / Q000737:chemistry
chemical_list: D008565:Membrane Proteins; D011725:Pyridines; D017971:Tin Compounds; D011193:Potassium Iodide; C109984:indium tin oxide; D006046:Gold; C023666:pyridine