We report the cyclohexanone and 3-aminopropyltrimethoxysilane (3-APTMS) mediated controlled synthesis of mixed nickel-iron hexacyanoferrate (Ni-Fehcf) nanosol of 34 nm average size. The new method allows the synthesis of a variety of mixed metal hexacyanoferrate (Mhcf) nanodispersion along with option for controlling the inversion of electrochemichemical behavior of Prussian blue(PB) into desired Mhcf. The typical process involves the mixing of 3-APTMS treated potassium ferricyanide with desired concentrations of nickel sulfate containing fixed amount of cyclohexanone resulting in a uniform spherical nanodispersion of mixed Ni-Fehcf. The different molar ratio of Ni : Fe (i.e. 1 : 1; 1 : 5 and 1 : 10) yielded a mixed Ni-Fehcf showing three different electrochemical properties ascribed to nickel hexacyanoferrate (Nihcf); both Nihcf and PB, and PB respectively. The mixed Ni-Fehcf resulting from a 1 : 5 Ni : Fe molar ratio has been found to be an excellent material for selective electroanalytic applications attributed to hydrogen peroxide and glutathione sensing due to the presence of PB and Nihcf behaviors respectively. The electrocatalytic property of Nihcf in mixed Ni-Fehcf is significantly better than that of conventional Nihcf for glutathione analysis and further increases on the incorporation of AuNPs.