Catalytic Performance of Oligonucleotide-Templated Pt Nanozyme Evaluated by Laccase Substrates

Laccases are effective native biocatalysts for the oxidation of o-/p-diphenols, aminophenols, polyphenols and polyamines. To overcome the intrinsic limitations of native laccase involving pH, temperature and storage, highly dispersive Pt nanoparticles were synthesized by employing different oligonucleotides as stabilizing agents including A(10), T-10, C-10 and G(10), and their catalytic activities were assessed in the oxidation of laccase substrates under ambient air. This kind of Pt nanozyme displays high stability in the range of 20-90 A degrees C and pH 3-9, beyond the range for native laccase. The laccase-like activities of Pt nanoparticles are greatly associated with the size distribution and the surface charge, which can be easily regulated by the sequence composition and the molar ratio of [precursor]/[template]. The most efficient C-10-templated Pt nanozyme with 4.6 nm in size, exhibit three times higher affinity toward 2,4-dichlorophenol than that of native laccase. DNA-stabilized Pt nanoparticles display excellent catalytic performance in the oxidation of a wide range of substrates including dopamine, catechol, hydroquinone and p-phenylenediamine. This study paves a way to explore artificial nanoparticles to replace native laccase in the fields of biosensing and green synthesis. [GRAPHICS] .