Artificial Biomimetic Electrochemical Assemblies

Rapid, selective, and cost-effective detection and determination of clinically relevant biomolecule analytes for a better understanding of biological and physiological functions are becoming increasingly prominent. In this regard, biosensors represent a powerful tool to meet these requirements. Recent decades have seen biosensors gaining popularity due to their ability to design sensor platforms that are selective to determine target analytes. Naturally generated receptor units have a high affinity for their targets, which provides the selectivity of a device. However, such receptors are subject to instability under harsh environmental conditions and have consequently low durability. By applying principles of supramolecular chemistry, molecularly imprinted polymers (MIPs) can successfully replace natural receptors to circumvent these shortcomings. This review summarizes the recent achievements and analytical applications of electrosynthesized MIPs, in particular, for the detection of protein-based biomarkers. The scope of this review also includes the background behind electrochemical readouts and the origin of the gate effect in MIP-based biosensors.

Voltage-driven mutual phase locking of planar nano-oscillators

Phase locking is a common phenomenon related to coupled oscillators that play an important role in various natural and artificial systems. In this study, we analyzed the possibility of dynamically controlling such a phenomenon between Gunn-effect-based planar nanooscillators via an ensemble Monte Carlo (EMC) method. We found that between two oscillators in parallel with each other, there are two coupling paths, which could be opened or closed via structure determined inner-field effect. One of the paths results in in-phase locking, and whereas the other gives rise to anti-phase locking. Furthermore, by combining the inner-field effect and a top-gate effect, one could dynamically control the phase locking via the top gate’s bias. EMC results showed that the transition time from in-phase to anti-phase locking can be less than 0.2 ns. Accompanied by this was a signal-frequency doubling, from approximately 0.33 THz to approximately 0.66 THz. Based on Adler’s theory, we confirmed the phase locking and concluded that the phase-locking transition could not be properly modeled unless electron-scattering noise was included. Moreover, we obtained the locking range and the frequency fluctuation due to electron-transport noise. The proposed method is convenient and may be applied to other electronic oscillators, thereby aiding in developing high-speed beam-steerable THz sources.

Manipulating the cross-layer channels in g-C3N4 nanosheet membranes for enhanced molecular transport

Cross-layer channels display ‘gate effect’ to govern molecular selectivity for lamellar membranes. Membranes with hydrophilic/hydrophobic heterostructured channels acquire elevated polar solvent permeance and polar/nonpolar solvents selectivity.

Research on the Preparation and Spectral Characteristics of Graphene/TMDs Hetero-structures

The Van der Waals (vdWs) hetero-structures consist of two-dimensional materials have received extensive attention, which is due to its attractive electrical and optoelectronic properties. In this paper, the high-quality large-size graphene film was first prepared by the chemical vapor deposition (CVD) method; then, graphene film was transferred to SiO2/Si substrate; next, the graphene/WS2 and graphene/MoS2 hetero-structures were prepared by the atmospheric pressure chemical vapor deposition method, which can be achieved by directly growing WS2 and MoS2 material on graphene/SiO2/Si substrate. Finally, the test characterization of graphene/TMDs hetero-structures was performed by AFM, SEM, EDX, Raman and PL spectroscopy to obtain and grasp the morphology and luminescence laws. The test results show that graphene/TMDs vdWs hetero-structures have the very excellent film quality and spectral characteristics. There is the built-in electric field at the interface of graphene/TMDs heterojunction, which can lead to the effective separation of photo-generated electron–hole pairs. Monolayer WS2 and MoS2 material have the strong broadband absorption capabilities, the photo-generated electrons from WS2 can transfer to the underlying p-type graphene when graphene/WS2 hetero-structures material is exposed to the light, and the remaining holes can induced the light gate effect, which is contrast to the ordinary semiconductor photoconductors. The research on spectral characteristics of graphene/TMDs hetero-structures can pave the way for the application of novel optoelectronic devices.