Carbon nanomaterials are at the forefront of the newest technologies of the third millennium, and together with conductive polymers, represent a vast area of indispensable knowledge for developing the devices of tomorrow. This review focusses on the most recent advances in the field of conductive nanotechnology, which combines the properties of carbon nanomaterials with conjugated polymers. Hybrid materials resulting from the embedding of carbon nanotubes, carbon dots and graphene derivatives are taken into consideration and fully explored, with discussion of the most recent literature. An introduction into the three most widely used conductive polymers and a final section about the most recent biological results obtained using carbon nanotube hybrids will complete this overview of these innovative and beyond belief materials.
Magnetism and the existence of magnetic order in a material is determined by its dimensionality. In this regard, the recent emergence of magnetic layered van der Waals (vdW) materials provides a wide playground to explore the exotic magnetism arising in the two-dimensional (2D) limit. The magnetism of 2D flakes, especially antiferromagnetic ones, however, cannot be easily probed by conventional magnetometry techniques, being often replaced by indirect methods like Raman spectroscopy. Here, we make use of an alternative approach to provide direct magnetic evidence of few-layer vdW materials, including antiferromagnets. We take advantage of a surfactant-free, liquid-phase exfoliation (LPE) method to obtain thousands of few-layer FePS3 flakes that can be quenched in a solvent and measured in a conventional SQUID magnetometer. We show a direct magnetic evidence of the antiferromagnetic transition in FePS3 few-layer flakes, concomitant with a clear reduction of the Néel temperature with the flake thickness, in contrast with previous Raman reports. The quality of the LPE FePS3 flakes allows the study of electron transport down to cryogenic temperatures. The significant through-flake conductance is sensitive to the antiferromagnetic order transition. Besides, an additional rich spectra of electron transport excitations, including secondary magnetic transitions and potentially magnon-phonon hybrid states, appear at low temperatures. Finally, we show that the LPE is additionally a good starting point for the mass covalent functionalization of 2D magnetic materials with functional molecules. This technique is extensible to any vdW magnetic family.
In recent years, 2D materials have been implemented in several applications due to their unique and unprecedented properties. Several examples can be named, from the very first, graphene, to transition-metal dichalcogenides (TMDs, e.g., MoS2), two-dimensional inorganic compounds (MXenes), hexagonal boron nitride (h-BN), or black phosphorus (BP). On the other hand, the accessible and low-cost 3D printers and design software converted the 3D printing methods into affordable fabrication tools worldwide. The implementation of this technique for the preparation of new composites based on 2D materials provides an excellent platform for next-generation technologies. This review focuses on the recent advances of 3D printing of the 2D materials family and its applications; the newly created printed materials demonstrated significant advances in sensors, biomedical, and electrical applications.
In this work, we present the combination of two different types of nanomaterials, 2D molybdenum disulfide nanosheets (MoS2-NS) and zero-dimensional carbon nanodots (CDs), for the development of a new electrochemiluminescence (ECL) platform for the early detection and quantification of the biomarker human epidermal growth factor receptor 2 (HER2), whose overexpression is associated with breast cancer. MoS2-NS are used as an immobilization platform for the thiolated aptamer, which can recognize the HER2 epitope peptide with high affinity, and CDs act as coreactants of the anodic oxidation of the luminophore [Ru(bpy)3]2+. The HER2 biomarker is detected by changes in the ECL signal of the [Ru(bpy)3]2+/CD system, with a low detection limit of 1.84 fg/mL and a wide linear range. The proposed method has been successfully applied to detect the HER2 biomarker in human serum samples.