Nano-biotechnology research has become extremely important due to the possibilities in manipulation and characterization of biological molecules through nanodevices. Nanomaterials exhibit exciting electrical, optoelectronic, magnetic, mechanical and chemical properties that can be exploited to develop efficient biosensors or bio-probes. Those unique properties in nanomaterials can also be used in bioimaging and cancer therapeutics, where biomolecules influence the inherent properties in nanomaterials. Effective manipulation of nanomaterial properties can lead to many breakthroughs in nanotechnology applications. Nowadays, 2D nanomaterials have emerged as viable materials for nanotechnology. Large cross-section area and functional availability of 2D or 1D quantum limit in these nanomaterials allow greater flexibility and better nanodevice performance. 2D nanomaterials enable advanced bioelectronics to be more easily integrated due to their atomic thickness, biocompatibility, mechanical flexibility and conformity. Furthermore, with the development of 2D material heterostructures, enhanced material properties can be obtained which can directly influence bio-nanotechnology applications. This article firstly reviews the development of various types of 2D heterostructures in a wide variety of nano-biotechnology applications. Furthermore, future 2D heterostructure scopes in bioimaging, nanomedicine, bio-markers/therapy and bioelectronics are discussed. This paper can be an avenue for providing a wide scope for 2D van der Waals (vdWs) heterostructures in bio- and medical fields.

Perovskites have recently attracted intense interests for optoelectronic devices application due to their excellent photovoltaic and photoelectric properties. The performance of perovskite-based devices highly depends on the perovskite material properties. However, the widely used spin-coating method can only prepare polycrystalline perovskite and physical vapor deposition (PVD) method requires a higher melting point (>350 °C) substrate due to the high growth temperature, which is not suitable for low melting point substrates, especially for flexible substrates. Here, we present the controlled synthesis of high quality two-dimensional (2D) perovskite platelets on random substrates, including SiO₂/Si, Si, mica, glass and flexible polydimethylsiloxane (PDMS) substrates, and our method is applicable to any substrate as long as its melting point is higher than 100 °C. We found that the photoluminescence (PL) characteristics of perovskite depend strongly on the platelets thickness, namely, thicker perovskite platelet has higher PL wavelength and stronger intensity, and thinner perovskite exhibits opposite results. Moreover, photodetectors based on the as-produced perovskite platelets show excellent photoelectric performance with a high photoresponsivity of 8.3 A·W⁻¹, a high on/off ratio of ~10³, and a small rise and decay time of 30 and 50 ms, respectively. Our approach in this work provides a feasible way for making 2D perovskite platelets for wide optoelectronic applications.

Graphene has become an emerging and promising option in the field of protection coating for anti-corrosion due to its specific properties in chemical inertia and physical impermeability. It can be applied to metal protection coating in forms of either atomically thin films or composite materials, known, respectively, as pure chemical vapour deposition (CVD) graphene coatings and graphene composite coatings (GCCs). Nonetheless, various structure defects, synthesis imperfections and graphene ^’ s positive potential to metals would make graphene-based protective coatings tend to exhibit corrosion promotion by arousing micro-galvanic corrosion, largely undermining its anti-corrosion efficiency. Based on this, many optimization strategies and methods have been conceived and applied to the graphene-based protection coatings in these two aspects for improving its anti-corrosion efficiency. For example, a good dispersion and orderly arrangement of graphene derivatives in the GCCs can largely optimize its anti-corrosion performance. Here, this paper separately reviews detailed optimization strategies, corresponding mechanisms and key factors for the use of representative graphene-based materials in these two aspects, with the aim of providing comprehensive knowledge and a roadmap of developing cheap, powerful and effective barrier technologies. Finally, perspectives on opportunities and challenges in improving the barrier coating efficiency of graphene-based materials are discussed.