Melamine-imprinted polymer grafts through surface photopolymerization initiated by aryl layers from diazonium salts

► Making of molecularly imprinted polymers via surface graft photopolymerization. ► Photo-initiators were grafted to gold through electroreduction of diazonium salts. ► MIP grafts are highly specific and selective towards melamine. ► MIP grafts show sub-nanomolar sensitivity to melamine in PBS or milk matrices.