DNA-Based Platinum Nanozymes for Peroxidase Mimetics

G-/C-rich oligonucleotides are chosen as the nucleation templates to synthesize Pt nanozymes with the size distribution of 1.7–2.9 nm, showing high activity to mimic peroxidase. The physicochemical properties including charge states and particle sizes are greatly associated with the DNA templates, the precursor ions as well as the molar ratios of [precursor]/[DNA]. As increasing the average size from 1.8 to 2.9 nm, the fraction of Pt0 species increases while the proportion of Pt2+ decreases. In the meanwhile, the Km value toward H2O2 decreases by three times, whereas toward TMB the Km increases by two times. The most efficient Pt nanozyme consisting of approximate 66% metallic Pt0 is stabilized by the i-motif RET2 with the average diameter of 2.9 nm. These results pave a promising way to manufacture metal nanozymes with facile modulation of physicochemical properties through programming DNA sequences.