Immobilization of His-Tagged Proteins on Various Solid Surfaces Using NTA-Modified Chitosan

Continued advancement of protein array, bioelectrode, and biosensor technologies will necessitate development of methods that allow for increased protein immobilization capacity and more control over protein orientation. Toward these ends, we developed a method involving modification of chitosan with nitrilotriacetic acid (NTA) to achieve immobilization of a larger amount of His-tagged protein than is possible with current methods. The immobilization capacity of our method was evaluated using His-tagged GFP (Green Fluorescent Protein) as a model protein. The average immobilization density on modified glass was about 32 ng/mm2. Our method is suitable for use on a variety of solid surfaces, including glassy carbon, silicon wafers, polycarbonate, and beaten gold.