“…For this aim, some strategies based on the identification of phosphate, which is transferred from ATP to the substrate peptides catalyzed by protein kinase, have been developed, such as fluorescence Zhou et al, 2013), electrochemiluminescence (Chen et al, 2013), quartz crystal microbalance (Xu et al, 2012), microarray-based resonance light scattering assay (Li et al, 2013b), photoluminescence , and electrochemistry (Li et al, 2013a;Wang et al, 2010;Xu et al, 2009;Yang et al, 2011). Among them, electrochemical strategy is proved to be a kind of promising way to achieve labelfree assay of protein kinase activity due to the advantages of easy operation, simple instrument, low cost and high sensitivity.…”