Our procedure is dramatically simpler than previously reported direct electrografting techniques for making diazonium-terminated films , and gives higher surface coverages of post-functionalization grafted groups. The procedure, to our knowledge, is the only single-step process reported to make diazonium-bearing thin films on both conducting and nonconducting substrates. Unlike diazo resins used for surface coatings, the grafting of PPBD produces a conjugated ultrathin film with control over the thickness of the final layer. Spontaneous surface grafting with PPBD produces a coating faster than most self-assembly methods, taking between 5-60 minutes to cover a surface. The technique can exceed a single monolayer in surface coverage and yields films with reasonably fast redox kinetics. While the synthesis of the coupling agent requires the use of acetic acid, the surface functionalization procedure itself can be carried out with no solvents other than water if the species to be immobilized is soluble in water, although the procedure works with nucleophiles in non-aqueous solvents as well. The procedure should complement existing techniques for producing diazonium-functionalized surface coatings, which generally require in situ diazotization of amine surfaces, 8 electrografting, or synthesis of a complex linker. We believe the technique is immediately applicable to the construction of electrochemical and optical sensors, as well as other devices involving immobilized complex molecules.