Hi,
I have two publications for you:
1. Ericsson, E. M., Enander, K., Bui, L., et al.; Site-Specific and Covalent Attachment of His-Tagged Proteins by Chelation Assisted Photoimmobilization: A Strategy for Microarraying of Protein Ligands. Langmuir 2013.
2. Willard, F. S. and Siderovski, D. P.; Covalent immobilization of histidine-tagged proteins for surface plasmon resonance. Analytical Biochemistry (353) 1: 147-149; 2006.
and a third where they oxidise the cobalt ion in order to make the interaction permanent:
3. Hale, J. E.; Irreversible, oriented immobilization of antibodies to cobalt-iminodiacetate resin for use as immunoaffinity media. Analytical Biochemistry (231) 1: 46-49; 1995.
Regards
Arnoud