In this study, a newly developed strategy is presented for phytase enzyme immobilization on a chemically modified cerium oxide nanoparticles decorated graphene oxide (CeO(2)NPs-GO) based on the surface of glassy carbon electrode (GCE). Fast Fourier transform square wave voltammetry (FFT-SWV) and cyclic voltammetry (CV) were used as detection techniques for phytic acid (PA) biosensor in [Fe(CN)(6)](3-/4-) solution. The decrease in current of [Fe(CN)(6)](3-/4-) solution toward increase in PA concentration on the CeO(2)NPs-GO electrode surface was elucidated in the range of 0.066 to 6.6 ppb with RSD of 3.8%. The newly developed PA biosensor provided a much lower detection limit (LOD = 0.001 ppb) than other reported electrochemical techniques for PA detection. Significant results were achieved using newly developed assay for detection of PA in spiked corn flour sample, which might be helpful in foods, feeds, livestock, agriculture and environmental sectors. No major organic compound, inorganic anions and cations were observed in the PA detection by using the proposed newly developed assay. (c) 2019 The Electrochemical Society.