title: Electrochemical synthesis of gold and protein gradients on particle surfaces.
abstract: A straightforward, versatile approach to the production of protein gradients on planar and spherical particle surfaces is described. The method is based on the spatially controlled oxidation of thiolated surfaces by Au(III) ions generated via the electrochemical oxidation of a gold electrode in a phosphate-buffered saline solution (10 mM PBS, pH 7.2, 150 mM NaCl). Because the gold electrode is in direct contact with the thiolated surfaces, the released Au(III) ions, which are present as Au(III) chloride complexes, give rise to the formation of a surface gradient of Au(I)-thiolate complexes depending on the local redox potential given by the local Au(III) concentration. As is shown on the basis of the use of X-ray photoelectron spectroscopy and fluorescently labeled proteins, the Au(I)-thiolate complexes can subsequently be functionalized with thiolated proteins, yielding surface density protein gradients on micrometer-sized nonconducting polymer beads as well as linear Au(I)-thiolate gradients on planar silicon surfaces.
authors: Department of Organic Chemistry, Stockholm University, Arrhenius Laboratory, SE-106 91 Stockholm, Sweden.
authors: Kristofer
authors: K
authors: Eriksson
authors: Pål
authors: P
authors: Palmgren
authors: Leif
authors: L
authors: Nyholm
authors: Sven
authors: S
authors: Oscarsson
mesh_terms: D055664:Electrochemical Techniques; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D010084:Oxidation-Reduction; D052638:Particulate Matter / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013499:Surface Properties
chemical_list: D052638:Particulate Matter; D011506:Proteins; D013438:Sulfhydryl Compounds; D006046:Gold