Colorimetric detection of bis-phosphorylated peptides using zinc(ii) dipicolylamine-appended gold nanoparticles

Protein phosphorylation plays an important role in intracellular signaling. Defects in the phosphorylation process, which are associated with cancers and other human diseases, can be reflected by the presence of abnormally phosphorylated peptides in serum. Therefore, phosphorylated peptides are important resources for biomarker discovery. However, few studies have been reported on developing sensors for phosphorylated peptides. In this study, zinc(ii) dipicolylamine-appended gold nanoparticles were synthesized and used for the colorimetric detection of bis-phosphorylated peptides. The addition of the bis-phosphorylated peptides could induce the aggregation of the functionalized AuNPs, and thus the color change of the gold colloid, while non-phosphorylated and mono-phosphorylated controls could not induce the color change.