A method of making a facile, surface-independent, polyphenol coating is disclosed. In general, the method includes contacting at least a portion of the substrate to be coated with an aqueous solution containing one or more salts and one or more nitrogen-free phenolic compounds. Substrates of all kinds may be used, and compounds used to make the coating may include epigallocatechin-3-gallate (EGCG), epigallocatechin (EGC) and epicatechin-3-gallate (ECG), tannic acid, gallic acid, pyrogallol, and/or other nitrogen-free phenolic compounds. The coating made using the method, methods of using the coating, and kits comprising the coating precursors are also disclosed.