Protein adsorption on the nickel-coated glass slide for protein chips

The adsorption of proteins on the surface of glass slides is essential for the construction of protein chips. Here, we report that a Histidine (His)-tagged protein has been efficiently adsorbed on glass slides coated with nickel. A variety of nickel chloride-coated plates were prepared by the spin-coating method and adsorbed to the His-tagged protein. When the protein was adsorbed onto the surface of a variety of nickel chloride-coated glass slides, the efficiency of protein adsorption was dependent upon the coating conditions such as nickel chloride concentration, the spin speed and the drying temperature. The slides appropriate for protein adsorption were obtained when the slides were coated with 11%(w/w) of NiCl₂ at the spin speed of 4000 rpm for 20 sec and then dried at higher than 40 °C. The physical properties of their nickel chloride thin layer were characterized by scanning electron microscopy, x-ray diffraction and atomic force microscopy, finding that the nickel chloride particles were around 10 nm in diameter and uniformly crystallized at 101 faces. These results show that nickel chloride-coated slides prepared by the spin-coating method are utilizable for the construction of His-tagged protein chips.