5-Hydroxymethyluracil
(5hmU) is an oxidation derivative of thymine
in the genomes of various organisms and may serve as both an epigenetic
mark and a cancer biomarker. However, the current 5hmU assays usually
have drawbacks of laborious procedures, low specificity, and unsatisfactory
sensitivity. Herein, we demonstrate the click chemistry-mediated hyperbranched
amplification-driven dendritic nanoassembly for genome-wide analysis
of 5hmU in breast cell lines and human breast tissues. The proposed
strategy possesses good selectivity, ultralow background, and high
sensitivity with a detection limit of 83.28 aM. This method can accurately
detect even a 0.001% 5hmU level in the mixture. Moreover, it can determine
5hmU at single-cell level and distinguish the expressions of 5hmU
in tissues of normal persons and breast cancer patients, holding great
promise in 5hmU-related biological research and clinical diagnosis.