Protein phosphorylation is a post-translational modification of kinase proteins that changes a protein's conformation to regulate crucial biological functions . However, the phosphorylation of protein is significantly altered during cancer progression which triggers abnormal cellular pathways and this phosphorylation can serve as an emergent diagnostic and prognostic biomarker for cancer . Herein, we develop a nanostructured mesoporous gold electrode (NMGE) -based biosensor that enables a highly sensitive detection of protein phosphorylation with electrochemical signal amplification . The biosensor comprises nanostructured mesoporous gold electrodes whose electro-conductive framework is superior to that of the nonporous electrodes . We characterize our developed nano/mesoporous gold electrode with various electrochemical methods in the presence of the [Fe (CN) 6] 3-/4- redox system . We find that the mesoporous gold electrode catalyzes both the oxidation and reduction processes of the [Fe (CN) 6] 3-/4- system and generates a current signal that is 3 times higher than that of the nonporous gold electrode . This superior signal transduction of our nano/mesoporous gold electrode is enabled through a pore-induced (i) high electrochemically active surface area and (ii) reduced impedance with a high signal to noise ratio . The assay utilizes direct adsorption of an immunoprecipitated purified BRAF protein towards the mesoporous gold electrode and thus avoids the cumbersome sensor surface functionalization . Our developed biosensor detects the phosphorylated BRAF protein with a 2.5-fold increase in sensitivity and an ≈10-fold increase in the limit of detection (LOD) in comparison with the nonporous gold electrodes . The assay also works on a wide dynamic range from 0.5 to 20 ng µL-1 of the protein which further shows its potential for clinical application . We envisage that this nanostructured mesoporous gold biosensor will be of high interest for clinical application.