This monograph discusses the advances of functional thin films for the sensors in analytical applications. It covers utilization of nanostructured films in the analytical signal enhancement, pre-concentration of analyte, pre-ionisation, lowering of desorption energy or recognition of certain analytes and performing of direct simple separation on these nanosubstrates. This monograph is focused on guidelines and design rules for nanostructured layers for SERS and SIMS applications. These two techniques are used in nanostructured layers functionality study. The next chapter provides a general description of basic principles of secondary ion mass spectrometry (static, dynamic, TOF-SIMS). Third chapter is devoted to the electrochemical deposition of SERS and SIMS active nanostructured silver films by several electrochemical techniques (cyclic voltammetry, potentiostatic and galvanostatic deposition). Monograph also includes special chapter on black silicon nanostructured films. Practical integration of nanostructured functional films into the analytical chip is described in the final chapter of the monograph.