Resonance Scattering Detection of Trace Hg2+ Using Aptamer-modified AuPd Nanoalloy Probe as Catalyst

摘要

The 5 nm AuPd nanoalloy in mole ratio of Au:Pd=32:1 was prepared, using sodium citrate as the stabilizing agent and NaBH₄ as the reductant. The AuPd nanoalloy was modified by the aptamer to prepare an aptamer- AuPd (AptAuPd) probe for resonance scattering (RS) detection of 5.0–1250 nmol/L Hg2+. The AptAuPd-Hg2+ aptamer reaction solution was filtrated by membrane, and the AptAuPd in the filtrate exhibited strong catalytic effect on the slow NiP particle reaction between NiCl₂ and NaH₂PO₂, and the NiP particles showed a RS peak at 508 nm. The RS intensity decreased when Hg2+ concentration increased. The decreased RS intensity was linear to Hg2+ concentration in the range of 0.5–1250 nmol/L. The RS assays were used to determine Hg2+ in real samples, with good results.