In this research, ZnO nanorods - Au nanoparticles nanohybrids have been fabricated and employed to sensitive electrochemical strategy for the specific detection of the ovarian cancer antigen CA-125/MUC126. The microdevice was developed in our lab based on gold and silver electrodes sputtered on glass substrate. The ZnO nanorods arrays were grown on working electrode using assisted microwave hydrothermal synthesis than gold nanoparticles (Au NPs) were deposited by sputtering. The Au NPs onto ZnO nanorods surface provides a favorable platform for efficient loading of anti-CA-125 antibody via binding with cystamine and glutaraldehyde. The effective loading of the biological material (CA-125 antibody and antigen) on the matrix was observed by SEM images. The electrochemical immunosensor shows a sensitive response to ovarian cancer antigen recombinant human CA-125/MUC126 with detection of 2.5ng/μL, 100 times lower than immunoblot system. Due to high specificity, reproducibility and noteworthy stability, the developed sensor will provide a sensitive, selective and convenient approach to be used to detect CA-125/MUC126.

Periodic structures induced by electron irradiation are a unique phenomenon when electron beams irradiate on the surface of some materials. These periodic structures have potential for technological applications. However, the fuzzy nature of the electron-induced structuring hinders its further exploration in such applications. In this paper, novel Ag nanoparticle/AgX (X=Cl, Br and I) composites, with enhanced photocatalytic activity and low toxicological effects, were prepared, for the first time, using electron beam irradiation. The remarkable advantage of this approach is that the Ag nanoparticles/AgX composites can be easily prepared in one-step without the need for high-pressure conditions, surfactants, ionic liquids, or reducing agents. Furthermore, our method does not involve any toxic substances, which makes the as-synthesized samples highly applicable for technological applications. The structure, morphology and physicochemical properties of the Ag nanoparticles/AgX composites were studied using various characterization techniques. Using first-principles calculations based on density functional theory and the quantum theory of atoms in molecules, we reveal how the concentration of excess electrons in the AgX materials induces the formation of the Ag nanoparticles under electron beam irradiation. These results extend the fundamental understanding of the atomic process underlying the mechanism of AgÀ X bond rupture observed during the transformation induced via electron irradiation of the AgX crystals by increasing the total number of electrons in the bulk structure. Thus, our findings provide viable guidance for the realization of new materials for the degradation of contaminated wastewater with low toxicity.

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In this work, a high photocatalytic activity was attained by intercalating a Pt layer between SnO 2 and TiO 2 semiconductors, which yielded a TiO 2 /Pt/SnO 2-type heterostructure used in the discoloration of blue methylene (MB) solution. The porous films and platinum layer were obtained by electrophoretic deposition and DC Sputtering, respectively, and were both characterized morphologically and structurally by FE-SEM and XRD. The films with the Pt interlayer were evaluated by photocatalytic activity through exposure to UV light. An increase in efficiency of 22% was obtained for these films compared to those without platinum deposition. Studies on the reutilization of the films pointed out high efficiency and recovery of the photocatalyst, rendering the methodology favorable for the construction of fixed bed photocatalytic reactors. A proposal associated with the mechanism is discussed in this work in terms of the difference in Schottky barrier between the semiconductors and the electrons transfer and trapping cycle. These are fundamental factors for boosting photocatalytic efficiency.

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