Nanomaterials

Negative photoconductivity (NPC) in low-dimensional materials has attracted considerable interest for its potential in novel optoelectronic devices. Here, we report an ultra-broadband NPC response in FePd₂Te₂, a van der Waals ferromagnet, spanning from visible to long-wavelength infrared at room temperature. The device achieves a responsivity of ~4.9 A/W and external quantum efficiency of ~240% at 2500 nm, with a noise-equivalent power (NEP) below 3.0 × 10⁻¹⁵ W/Hz^1/2 and a specific detectivity (D*) exceeding 3.6 × 10¹¹ cmHz^1/2/W across the infrared range. Systematic measurements identify the photobolometric effect as the underlying mechanism, wherein wavelength-dependent absorption depths play a key role in shaping the photoresponse characteristics. These results establish FePd₂Te₂ as a promising platform for uncooled broadband infrared detection and highlight the potential of magnetic van der Waals materials for future optoelectronics.

DNA has evolved from a carrier of genetic information into a programmable material for constructing nanoscale architectures with precise structural and functional control. Among these systems, tetrahedral DNA nanostructures (TDNs) comprise at least two experimentally distinct structural families: small scaffold-free tetrahedra assembled from a few synthetic oligonucleotides, often termed tetrahedral framework nucleic acids (tFNAs), and larger scaffolded or wireframe tetrahedral DNA-origami objects. This review integrates assembly principles, computational and sequence-level design, physicochemical stability, fabrication, structural validation, biological performance, and translational evidence while keeping these two families analytically separate. For few-strand TDNs, particular attention is given to ionic conditions, pH, temperature, serum and nuclease exposure, cellular uptake, targeting aptamers, and delivery of drugs and regulatory nucleic acids; scaffolded tetrahedral origami is discussed where its routing, mechanics, manufacturing, or larger spatial capacity are directly relevant. Recent in vivo studies provide evidence for tissue distribution, transdermal delivery, and short-term biocompatibility of selected few-strand TDN formulations, but the translational evidence remains predominantly preclinical. Rather than positioning TDNs as universally superior nanocarriers, this review emphasizes architecture-specific evidence, quantitative experimental conditions, and the limits of transferring conclusions between structural families. Progress toward translational nanomedicine will require validated design rules, matched-condition benchmarking, pharmacokinetic and biodistribution studies, scalable manufacturing, standardized quality attributes, and rigorous safety assessment.

Molecular dynamics simulations were employed to investigate the effects of cutting speed and cutting depth on the nanocutting behavior of carbon nanotube (CNT)-reinforced Ni composites. The results show that increasing cutting speed from 50 to 200 m/s reduces the average tangential cutting force by approximately 16.5%, while the cutting temperature increases by 26.7% at a cutting distance of 200 Å. Cutting depth produces a stronger influence on subsurface deformation, with deeper cutting accompanied by increased stress localization, structural disorder, and dislocation activity. In contrast, dislocation evolution exhibits a non-monotonic dependence on cutting speed, indicating that thermal and mechanical effects act concurrently under different cutting conditions. Pronounced changes in local deformation and dislocation behavior are also observed near the CNT–matrix region. These results characterize the coupled thermomechanical and defect responses of the selected CNT–Ni system under different nanocutting conditions.