NOVELTY - Proton and/or cation transfer polymer comprising one of 3-hydroxy-benzaldehyde, 4-acetyl-3-hydroxy-benzaldehyde and 2-hydroxy-benzaldehyde, is new.    USE - The proton and/or cation transfer polymer is useful: in an electrochemical system; an electrode for an electrochemical sensor for sensing an analyte in a solution; a polymeric film of an energy device; and a lithium battery (all claimed), where the electrochemical sensor is a pH sensor.    ADVANTAGE - The proton and/or cation transfer polymer ensures rapid and instantaneous measurement/detection of the analyte in the solution with high accuracy and without interferences.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) an electrode for an electrochemical sensor for sensing an analyte in a solution, comprising a substrate, and layers of a polymer sensitive to the analyte, where the polymer sensitive to the analyte comprises a redox sensitive moiety that is sensitive to the analyte and a facilitator of proton transfer that facilitates proton transfer from the solution to the substrate, and the layers of the polymer sensitive to the analyte passivates a transfer of electrons from the solution to the substrate;    (2) producing a coated substrate for an electrochemical system, comprising contacting a conductive substrate with a proton/cation transfer facilitator polymer, and repeatedly electrochemically oxidizing the polymer to form a multilayer of the proton/cation transfer facilitator polymer on the conductive substrate;    (3) sensing an analyte in a solution, comprising contacting an electrode comprising the layers of a polymer comprising a coordinating group with respect to an ion of interest and a proton transfer facilitating group/moiety with the solution, and measuring electrical properties of an oxidation and/or reduction of the coordinating group;    (4) a polymeric film of an energy device, comprising a polymer configured to provide for the transfer/movement of cations (lithium, hydrogen ions (H+)) through the polymer from a first electrode to a second electrode; and    (5) a battery comprising a first electrode, a second electrode, and the polymeric film disposed between the first and the second electrodes.