DJL

The discrete cavity of a self-assembled palladium–tris(4-pyridyl)triazine cage dictates the ratio of metal, ligand, and a non-coordinative molecule in the formation of silver(I)–dialkyl chalcogenide (Et, nBu; S, Se) complexes and defines their coordination arrangement.

Complexed in a complex: Complexation of a silver(I) ion with dialkyl chalcogenides is performed in the cavity of a self-assembled cage. This method modulates the number and geometry of the chalcogenides coordinated to silver(I) and generates a metal–organic proximal state.

In this work, novel three-dimensional graphene films (3D GFs) with controllable pore structures are directly fabricated on gold substrates through the hydrothermal reduction. An interfacial technique of the self-assembled monolayer is successfully introduced to address the binding issue between the graphene film and substrate. Adscititious silica spheres, serving as new connection centers, effectively regulate the dimensions of framework in graphene films, and secondary pore structures are produced once removing the spheres. Based on hierarchically porous 3D GFs with large surface area, excellent binding strength, high conductivity, and distinct interfacial micro-environments, selected examples of electrochemical aptasensors are constructed for the assay of adenosine triphosphate (ATP) and thrombin (Tob) respectively. Sensitive ATP and Tob aptasensors, with high selectivity, excellent stability, and promising potential in real serum sample analysis, are established on 3D GFs with different structures. The results demonstrate that the surface area, as well as interfacial micro-environments, plays a critical role in the molecular recognition. The developed reliable and scalable protocol is envisaged to become a general path for in situ fabrication of more graphene films and the as-synthesized 3D GFs would open up a wide horizon for potential applications in electronic and energy-related systems.

Three dimensional graphene film s (GFs) with controllable pore structures are directly fabricated on the gold substrate through a facile and reliable approach. The resulting GFs exhibit large surface area, excellent binding strength and high conductivity, which will enable many advanced applications in electronic and energy-related systems. As examples, novel electrochemical aptasensors with high performance are constructed in this work.

Van der Waals heterostructures designed by assembling isolated two-dimensional (2D) crystals have emerged as a new class of artificial materials with interesting and unusual physical properties. Here, the multilayer MoS₂–WS₂ heterostructures with different configurations are reported and their optoelectronic properties are studied. It is shown that the new heterostructured material possesses new functionalities and superior electrical and optoelectronic properties that far exceed the one for their constituents, MoS₂ or WS₂. The vertical transistor exhibits a novel rectifying and bipolar behavior, and can also act as photovoltaic cell and self-driven photodetector with photo-switching ratio exceeding 10³. The planar device also exhibits high field-effect ON/OFF ratio (>10⁵), high electron mobility of 65 cm²/Vs, and high photo­responsivity of 1.42 A/W compared to that in isolated multilayer MoS₂ or WS₂ nanoflake transistors. The results suggest that formation of MoS₂–WS₂ heterostructures could significantly enhance the performance of optoelectronic devices, thus open up possibilities for future nanoelectronic, photovoltaic, and optoelectronic applications.

Newly designed MoS ₂ –WS ₂ heterostructures perform novel and enhanced optoelectronic performances. Vertical transistors possess new functionalities such as rectifying, bipolarity, photovoltaic effect, and self-driven photodetection. Planar devices exhibit superior optoelectronic properties with high field-effect ON/OFF ratio (>10⁵), electron mobility of 65 cm²/Vs, and photoresponsivity of 1.42 A/W that far exceed the one for their constituents MoS₂ or WS₂.

For patients who suffer from sensorineural hearing loss by damaged or loss of hair cells in the cochlea, biomimetic artificial cochleas to remedy the dis­advantages of existing implant systems have been intensively studied. Here, a new concept of an inorganic-based piezoelectric acoustic nanosensor (iPANS) for the purpose of a biomimetic artificial hair cell to mimic the functions of the original human hair cells is introduced. A trapezoidal silicone-based membrane (SM) mimics the function of the natural basilar membrane for frequency selectivity, and a flexible iPANS is fabricated on the SM utilizing a laser lift-off technology to overcome the brittle characteristics of inorganic piezoelectric materials. The vibration amplitude vs piezoelectric sensing signals are theoretically examined based on the experimental conditions by finite element analysis. The SM is successful at separating the audible frequency range of incoming sound, vibrating distinctively according to varying locations of different sound frequencies, thus allowing iPANS to convert tiny vibration displacement of ≈15 nm into an electrical sensing output of ≈55 μV, which is close to the simulation results presented. This conceptual iPANS of flexible inorganic piezoelectric materials sheds light on the new fields of nature-inspired biomimetic systems using inherently high piezoelectric charge constants.

The new concept of a biomimetic artificial hair cell using a flexible inorganic piezoelectric acoustic nanosensor (iPANS) is presented. A highly sensitive flexible piezoelectric sensor that responds to sound-driven vibrations of a thin silicone membrane is fabricated using a laser lift-off process. The iPANS shows remarkable capability to sense tiny vibrations caused by an external sound wave.