Here we show an intriguing phenomenon in the bubble electrospinning process that the ruptured film might be stripped upwards by an electronic force to form a very thin and long plate-like strip, which might been received in the metal receiver as discontinuous backbone-like wrinkled materials, rather than smooth nano-fibers or microspheres. The processes are called the bubble electrospinning. The electronic force can be replaced by a blowing air, and the process is called as the blown bubble spinning. We demonstrate that the size and thickness of the ruptured film are the crucial parameters that are necessary to understand the various observations including beads and nanoporous materials. We identify the conditions required for a ruptured film to form discontinuous structure, and a critical width of the ruptured film to form a cylindrical fiber, above which a long and thin plate-like strip might be obtained, and a criterion for oscillatory jet diameter, which leads to bead morphology of the obtained fibers. The space of the adjacent beads depends on the fiber size. We anticipate our assay to be a starting point for more sophisticated study of the bubble electrospinning and the blown bubble spinning and for mass-production of both nanofibers and nanoscale discontinuous materials

Ultrathin two-dimensional metal–organic frameworks (2D MOFs) have recently attracted extensive interest in various catalytic fields (e.g., electrocatalysis, photocatalysis, thermocatalysis) due to their ultrathin thickness, large surface area, abundant accessible unsaturated...

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Herein, novel photoactive materials, nitrogen-doped porous carbon-ZnO (NPC-ZnO) nanopolyhedra, were prepared by direct carbonization of zeolitic imidazolate framework (ZIF)-8 nanopolyhedra in a nitrogen atmosphere. The morphology, structure, and photoelectrochemical (PEC) properties were characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, nitrogen adsorption-desorption method, and PEC methods. The results showed that the obtained NPC-ZnO nanopolyhedra had a rhombic dodecahedron morphology with uniform particle size of about 100 nm and a high surface area of 609.2 m g. Under visible-light irradiation, the NPC-ZnO nanopolyhedra showed better PEC performance than ZnO nanorod and the ZIF-8 nanopolyhedra in aqueous media with dissolved oxygen and ascorbic acid. Taking alkaline phosphatase (ALP) as a model, a NPC-ZnO nanopolyhedra-based PEC sensor was developed and showed good performance for ALP assay with a wide linear response range from 2 to 1500 U L and a low detection limit of 1.7 U L. Moreover, the PEC sensor possessed acceptable selectivity, reproducibility, and stability. The prepared NPC-ZnO nanopolyhedra provide a new photoactive material for the construction of PEC sensors and may have promising applications in PEC assay of heavy metal ions, organic pollutants, and biomolecules.

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Recently, easy, green, and low-cost liquild exfoliation of bulk materials to obtain thin-layered nanostructure significantly emerged. In this work, thin-layered molybdenum disulfide (MoS2) nanosheets were fabricated through intercalation of self-doped polyaniline (SPAN) to layer space of bulk MoS2 by ultrasonic exfoliating method to effectively prevent reaggregation of MoS2 nanosheets. The obtained hybrid showed specific surface area, a large number of electroactive species, and open accessible space, accompanied by rich negative charged and special conjugated structure, which was applied to adopt positively charged guanine and adenine, based on their strong π-π* interactions and electrostatic adsorption. Also, the SPAN-MoS2 interface exhibited the synergistic effect and good electrocatalytic activity compared with the sole SPAN or MoS2 modified electrode.

A new photoelectrochemical biosensor based on a CdSe QD//NPC-ZnO polyhedra photocurrent-direction switching system and a target-triggered strand displacement amplification strategy was developed for the detection of miRNA-155.