Catalysis of aptamer-modified AuPd nanoalloy probe and its application to resonance scattering detection of trace UO22+

Abstract

AuPd nanoalloy and nanopalladium with a diameter of 5 nm were prepared, using sodium citrate as the stabilizing agent and NaBH₄ as the reductant. The nanocatalyst containing palladium on the surface exhibited a strong catalytic effect on the slow NiP particle reaction between NiCl₂ and NaH₂PO₂, and the NiP particle system showed a resonance scattering (RS) peak at 508 nm. The RS results showed that the Pd atom on AuPd nanoalloy surface is the catalytic center. Combining the aptamer cracking reaction of double-stranded DNA (dsDNA)-UO₂²⁺, AuPd nanoalloy aggregation, and AuPd nanoalloy catalysis, both AuPd nanoalloy RS probe and AuPd nanoalloy catalytic RS assays were developed for the determination of 40–250 pmol L⁻¹ UO₂²⁺ and 5.0–50 pmol L⁻¹ UO₂²⁺, respectively.