Gold Nanoparticles -coated capillaries for protein and peptide analysis on open-tubular capillary electrochromatography

MARIANA HAMER; ANGEL YONE; IRENE N. REZZANO

Hollywood, Florida

Simposio; 17th Latin - American Symposium on Biotechnology, Biomedical, Biopharmaceutical and Industrial Applications of Capillary Electrophoresis and Microchip Technology; 2011

We report a new method of immobilization of gold nanoparticles on a fused silica capillary though covalent binding. The resulting modified capillary was applied to an electrophoretic system to improve the efficiency of separation and the selectivity of selected solutes. The immobilization of AuNPs on the capillary wall was performed in a very simple and fast way without requiring heating. The surface features of an AuNPs-coated capillary column were determined using scanning electron microscopy. The chromatographic properties of AuNPs-coated capillaries were investigated through variation of the phosphate buffer pH from 4.0 to 8.0. The fused silica capillaries had a 75 μm i.d.x 41.2 cm total length (31 cm effective length). The running condition was 12kV, 25°C, with UV detection at 214 nm. Effective separations of synthetic peptides mixture were obtained on the AuNPs- coated capillaries. The method shows a remarkable stability since it was reused about 900 times. The capacity factor was duplicated. Therefore this modification is stable and can be applied to different separation purposes. A complex mixture of tryptic peptide fragments of HSA was analyzed in both the bare and the AuNPs-coated capillaries. Better electrophoretic peptide profile was observed when using the AuNPs-coated capillary.