The present invention provides a dense-coverage, adherent phosphorous-based coating on the native oxide surface of a material. Disclosed phosphorous-based coatings include phosphate and organo-phosphonate coatings. The present invention also provides further derivatization of the phosphorous-based coatings to yield dense surface coverage of chemically reactive coatings and osteoblast adhesion-promoting and proliferation-promoting coatings on the native oxide surface of a titanium material.