Herein we designed a novel photoelectrochemical sensing platform based on Fe 3+ doped ZnO-Ag photocatalyst (Fe 3+ /ZnO-Ag) for ultrasensitive Hg 2+ detection by using exonuclease III-assisted target recycling and DNAzyme-catalyzed amplification. Firstly, Fe 3+ /ZnO-Ag was synthesized to provide photocurrent under visible light irradiation. Secondly, target Hg 2+ was determined by hairpin DNA probes on the Fe 3+ /ZnO-Ag modified ITO based on T-Hg 2+ -T, and then Hg 2+ was released by the digestion of exonuclease III to double-stranded DNA. Finally, the photocurrent markedly decreased due to catalysis of hemin/G-quadruplex toward 4-chloro-1-naphthol. Under optimal conditions, the photocurrents were linearly related to Hg 2+ concentrations form 0. 5 nM to 100 nM with a detection limit of 0. 1 nM at the 3 S blank criterion. More importantly, the developed biosensor exhibited good selectivity, repeatability, and stability, meanwhile, this analysis platform held great potential for testing real water samples in future.
Haihui Shen,Bo Zhang,Huiyan Xu,Yue Sun,Qiwang Wu,Hong Shen,Yingchun Liu
Some natural heterocyclic alkaloids containing planar group show potential to complex with specific promoter region of protooncogene for stabilizing the G-quadruplex (G4) structure which nowadays promises to be a target in anticancer drug design. However, in view of the polymorphic characteristics and structural complexity of heterocyclic alkaloids, it is desirable to develop high-throughput and low-consumption approach for anticancer drug screening. In this paper, an intensive study on alkaloid ligand/G4 DNA interaction has been conducted, demonstrating that the end-stacking interaction is the favorable binding mode between the oncogene-related Pu22 G4 DNA and the heterocyclic alkaloid ligand. Based on structural feasibility and energy minimization, a ligand displacement assay for screening alkaloid ligand in stabilizing the oncogene target G4 has been developed, which also helps to facilitate the assessment of drug specificity. Coupled with microfluidic-based DNAzyme-catalytic chemiluminescence detection, the approach showed the advantages of high sensitivity, high throughput with low sample and reagent consumptions.
危险品化学品经营许可证（带存储）