Precisely controlled spatial distributions of artificial light-harvesting systems in aqueous media are of significant importance for mimicking natural light-harvesting systems; however, they are often restrained by the solubility and the aggregation-caused quenching effect of the hydrophobic chromophores. Herein, we report one highly efficient artificial light-harvesting system based on peptoid nanotubes that mimic the hierarchical cylindrical structure of natural systems. The high crystallinity of these nanotubes enabled the organization of arrays of donor chromophores with precisely controlled spatial distributions, favoring an efficient Förster resonance energy transfer (FRET) process in aqueous media. This FRET system exhibits an extremely high efficiency of 98.6% with a fluorescence quantum yield of 40% and an antenna effect of 29.9. We further demonstrated the use of this artificial light-harvesting system for quantifying miR-210 within cancer cells. The fluorescence intensity ratio of donor to acceptor is linearly related to the concentration of intercellular miR-210 in the range of 3.3–156 copies/cell. Such high sensitivity in intracellular detection of miR-210 using this artificial light-harvesting system offers a great opportunity and pathways for biological imaging and detection, and for the further creation of microRNA (miRNA) toolbox for quantitative epigenetics and personalized medicine.

Single-atom catalyst (SAC) is one of the newest catalysts, and attracts people’s wide attention in cancer therapy based on their characteristics of maximum specific catalytic activity and high stability. We designed and synthesized a Fe-N decorated graphene nanosheet (Fe-N₅/GN SAC) with the coordination number of five. Through enzymology and theoretical calculations, the Fe-N₅/GN SAC has outstanding intrinsic peroxidase-like catalytic activity due to single-atom Fe site with five-N-coordination structure. We explored its potential on lung cancer therapy, and found that it could kill human lung adenocarcinoma cells (A549) by decomposing hydrogen peroxide (H₂O₂) into toxic reactive oxygen species (ROS) under acidic microenvironment in three-dimensional (3D) lung cancer cell model. Our study demonstrates a promising application of SAC with highly efficient single-atom catalytic sites for cancer treatment.

The synergistic therapy of chemotherapy and photothermal therapy (PTT) has been reported as a promising antitumor strategy. To achieve effective combination therapy, developing more suitable candidate nanomaterials with optimal photothermal property and high chemical drug loading capacity is very necessary. Herein, a bimetallic PtPd nanoparticle was synthesized with the merits of excellent photothermal effect and mesoporous structure for doxorubicin (DOX) loading. We further designed PtPd-ethylene glycol (PEG)-folic acid (FA)-doxorubicin (DOX) nanoparticle for chemo-photothermal therapy of MCF-7 tumor with folic acid engineering to achieve active targeting. Moreover, excellent photoacoustic (PA) imaging of PtPd-PEG-FA-DOX nanoparticles facilitated the precise in vivo tracking and further evaluation of nanoparticles’ targeting effect. The in vitro and in vivo results both demonstrated PtPd-PEG-FA-DOX nanoparticles serve as a safe and promising system for effective treatment of MCF-7 tumor.

SnO₂ is a promising material for both Li-ion and Na-ion batteries owing to its high theoretical capacities. Unfortunately, the electrochemical performance of SnO₂ is unsatisfactory because of the large volume change that occurs during cycling, low electronic conductivity of inactive oxide matrix, and poor kinetics, which are particularly severe in Na-ion batteries. Herein, ultra-fine SnO₂ nanocrystals anchored on a unique three-dimensional (3D) porous reduced graphene oxide (rGO) matrix are described as promising bifunctional electrodes for Li-ion and Na-ion batteries with excellent rate capability and long cycle life. Ultra-fine SnO₂ nanocrystals of size ~6 nm are well-coordinated to the graphene sheets that comprise the 3D macro-porous structure. Notably, superior rate capability was obtained up to 3 C (1/n C is a measure of the rate that allows the cell to be charged/discharged in n h) for both batteries. In situ X-ray diffractometry measurements during lithiation (or sodiation) and delithiation (or desodiation) were combined with various electrochemical techniques to reveal the real-time phase evolution. This critical information was linked with the internal resistance, ion diffusivity (D_Li⁺ and D_Na⁺), and the unique structure of the composite electrode materials to explain their excellent electrochemical performance. The improved capacity and superior rate capabilities demonstrated in this work can be ascribed to the enhanced transport kinetics of both electrons and ions within the electrode structure because of the well-interconnected, 3D macro-porous rGO matrix. The porous rGO matrix appears to play a more important role in sodium-ion batteries (SIBs), where the larger mass/radius of Na-ions are marked concerns.

Heteroatom doping, precise composition control, and rational morphology design are efficient strategies for producing novel nanocatalysts for the oxygen reduction reaction (ORR) in fuel cells. Herein, a cost-effective approach to synthesize nitrogen- and sulfur-codoped carbon nanowire aerogels using a hard templating method is proposed. The aerogels prepared using a combination of hydrothermal treatment and carbonization exhibit good catalytic activity for the ORR in alkaline solution. At the optimal annealing temperature and mass ratio between the nitrogen and sulfur precursors, the resultant aerogels show comparable electrocatalytic activity to that of a commercial Pt/C catalyst for the ORR. Importantly, the optimized catalyst shows much better long-term stability and satisfactory tolerance for the methanol crossover effect. These codoped aerogels are expected to have potential applications in fuel cells.