the present invention relates to methods of making nanoarrays for use in detecting species formed on the surface of the array using sers . the methods can involve nanolithographic printing of a compound by dip pen nanolithographic printing . a sers substrate can be used for the array and which can be selected from surfaces roughened by the oxidation - reduction cycle , island films , colloidal nanoparticles and surface - confined nanostructures . a coating or intermediate layer , such as a layer formed of nitrocellulose , can be provided between the compound and the sers substrate . there are also provided arrays themselves and methods of using such arrays .