protein phosphorylation is a major post - translational modification and it plays a pivotal role in numerous cellular functions . we present a composition that includes a soluble nanopolymer core functionalized with groups having an affinity for either metal ion or metal oxides which can be used for phosphopeptide enrichment . exemplary compounds including polymac - zr , polymac - fe and polymac - ti demonstrate outstanding reproducibility , exceptional sensitivity , fast chelation time , and high phosphopeptide recovery from standard mixtures that include phosphorylated peptides . the composition can be used for phosphoproteome isolation from samples of medicinal , diagnostic or biological interest such as malignant breast cancer cells . such compositions were used for the quantitative analysis of the changes in the tyrosine phosphoproteome in highly invasive breast cancer cells after induction of syk kinase , a potent suppressor of tumor growth and metastasis . the composition and method disclosed herein offers an efficient and widely applicable tool for phosphoproteomics .