Yujie Yu,Chao Yu,Yazhen Niu,Jun Chen,Yilin Zhao,Yuchan Zhang,Rufei Gao,Junlin He
We designed an amplified detection strategy for the sensitive determination of lead ions (Pb 2+ ) based on a target-triggered nuclear acid cleavage of Pb 2+ -specific DNAzyme as a selectivity interface combined with Pd-Pt alloys modified Fe-MOFs (Fe-MOFs/PdPt NPs) hybrids acting as the signal tag. Streptavidin modified reduced graphene oxide-tetraethylene pentamine-gold nanoparticles (rGO-TEPA-Au) served as a sensor platform for immobilizing more DNAzyme. In the presence of Pb 2+ , the substrate DNA strand can be specifically cleaved at the ribonucleotide site by DNAzyme to produce a new single-DNA on the interface. Then, the hairpin DNA with hybrid strand matched by its complement to the single-DNA was employed to modify the Fe-MOFs/PdPt NPs bioconjugates for signal amplification . Fe-MOFs/PdPt NPs catalyze hydrogen peroxide (H 2 O 2 ) to produce the electrochemical signal which was recorded by chronoamperometry . Benefiting from the Pb 2+ -dependent DNAzyme, the proposed method can selectively detect Pb 2+ in the presence of other metal ions . The newly designed biosensor exhibited a good linear relationship ranging from 0.005 to 1000 nmol L −1 with a low detection limit of 2 pM (S/N = 3) for Pb 2+ . This Pb 2+ -dependent DNAzyme based ultrasensitive biosensor showed high sensitivity and selectivity, providing potential application for Pb 2+ detection in naturally contaminated sewage and spiked drinking water samples.
Multimetallic plasmonic nanostructures, with appropriate morphology, elemental proportions and sizes, can be used to accelerate photocatalytic reactions. Here, we designed zigzag trimetallic nanostructures with the Au core and Pd–Pt alloy shell, whose catalytic ability was boosted by the synergistic effect of the plasmonic metal and catalytic metal. The catalytic rate of Au@PdPt nanoparticle (NP) with no light have a significant improvement, attributed to the larger contact area provided by the zigzag alloy shell. Furthermore, the enhanced catalytic activity in the presence of light is primarily due to the thermo-photo catalytic effect of plasmonic Au. The adding ratios of Pd:Pt were adjusted from 1:4 to 4:1, and we found that, when adding the Pd:Pt of 1:1, the zigzag Au@PdPt nanoparticle (NP) exhibited a superior reaction rate in the reduction methylene blue (MB) under light illumination. The rate is 8 times higher than that of Au@Pt, and the reduction conversion reached 100%. And it has a favorable plasmon enhancement factor with an appropriate shell thickness and get the balance between the catalytic performance and economic effects. This structure driven by capability-oriented design principles and holds the potential for applications in the field of catalysis. Graphical abstract
危险品化学品经营许可证（带存储）