Fabrication of functional electrochemical biosensor is a hot topic; however, precise and sensitive cancer detection in early clinical diagnosis is still a great challenge. Continuous efforts have been devoted to explore functional materials for this issue. In this work, we developed a dual binding sites and dual signal-amplifying electrochemical aptasensor of self-polymerized dopamine-decorated Au and coordinated with Fe-MOF (Au@PDA@Fe-MOF) for the detection of carcinoembryonic antigen (CEA). Remarkably, Au@PDA@Fe-MOF features high sensitivity, multiple active sites, good biocompatibility, and excellent selectivity, which is attributed to abundant −COOH in porous Fe-MOF and unsaturated Fe3+ sites on the surface of Fe-MOF as the active binding sites grafting more NH2-functionalized CEA-specific aptamer and redox PDA and Fe-MOF accelerating the movement of electrons for dual signal amplifying. Meanwhile, the electrochemical aptasensor shows favorable repeatability with 1.82% relative standard deviation (RSD) under five independent aptasensors and strong stability with only 3.3% degradation after 12 days of storage. In addition, the aptasensor has wide CEA detection range from 1 fg mL–1 to 1 μg mL–1 with a low detection limit of 0.33 fg mL–1 (S/N = 3). Furthermore, the aptasensor is feasible for accurate and quantitative detection of CEA in serum samples with RSD below 2.32%. The satisfying results demonstrate promising applications of the CEA aptasensor in practical sample analysis and lay an important foundation for other biomarker detection in early clinical diagnosis.

A porous core–shell nanocatalyst hydrazine hydrate water system has been developed for the catalytic transfer hydrogenation of nitroarenes.

Fabrication of anilines from the corresponding nitroaromatics is a hot topic both for academia and for industry; however, conducting this protocol in water over a noble-metal-free catalytic system is still a great challenge. Continuous efforts are being made on exploiting novel catalysts for this transformation. In this work, we developed a scalable method for synthesizing the uniform flowerlike amorphous α-FeOOH hierarchical supraparticles. The well-defined amorphous α-FeOOH was prepared through an environmentally benign method, which is hydrolysis of the self-assembled iron glycolate at room temperature. Compared with other iron-only catalysts, this flowerlike amorphous α-FeOOH hierarchical supraparticle catalyst exhibits the best performance in the catalytic reduction of nitroaromatics to corresponding anilines by using water as the reaction solvent (turn over frequency is 106 h for 4-nitrophenol in water). The further results indicated that the amorphous structure, special nanostructures, and adsorption-desorption synergy offered excellent activity. The kinetics study shows that the reduction of 4-nitrophenol is first order for α-FeOOH, and the apparent active energy E is 75.9 kJ mol. Furthermore, this catalyst can be used for eight times without obvious catalytic activity loss. We believe that this novel flowerlike amorphous α-FeOOH hierarchical supraparticle catalyst is a milestone in the reduction of nitro compounds.