Platforms for easy and cost-effective fabrication of bio-microarrays are disclosed. In one embodiment, the platform contains a substrate having a surface coated with a film of alternating polycationic and polyanionic polymers. In another embodiment, the platform contains a substrate having a surface coated with a polyelectrolyte-silica sol-gel film. Also disclosed are bio-microarrays fabricated using the above platforms and methods of making the platforms and the microarrays.
 This invention was made with United States government support awarded by the following agency: Department of Energy, Grant Number KP1301010. The United States has certain rights in this invention.