Methods, particles and kits for determining kinase activity within a sample are provided. An embodiment of a method includes exposing a fluorescent particle to an assay, wherein the fluorescent particle includes a support substrate having one or more fluorescent materials and a peptide substrate coupled to the support substrate via a functional group of the support substrate. The method further includes phosphorylating the peptide substrate during exposure of the fluorescent particle to the assay and processing the fluorescent particle such that the peptide substrate is dephosphorylated and a polarized double bond is generated at a dephosphorylated site. In addition, the method includes coupling a fluorescent reporter having a nucleophilic terminal group to the fluorescent particle via the polarized double bond.