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A comprehensive theoretical study on Cu-based single-atom alloys reveals their inherent structure–activity relationship relevant to performance in NRR.

Reducing the usage of Pt for the oxygen reduction reaction (ORR) is of great significance for the commercialization of proton exchange membrane fuel cells.

The fabrication of an organic-inorganic nanocomposite hydrogel platform with antibacterial, anti-inflammatory, and osteoinductive properties that mimic bone extracellular matrix composition, is decisive for the guiding bone development in orthopedic practice....

Ammonia synthesis by the electrochemical technique is a promising solution to replace the energy-intensive Haber–Bosch process in industry, which inevitably requires high-performance catalysts. However, the development of catalysts is still limited by the inferior activation of the stable NN bond. Herein, a robust N2-activation mode is proposed, which addresses the electron donation mechanism to both the N2 antibonding orbitals of py and pz, simultaneously. Following this strategy, the single cluster catalyst (SCC) of Fe4/GaS has realized remarkable nitrogen reduction reaction (NRR) performance with an ultra-low overpotential (η) of 0.08 V by density functional theory (DFT) calculations. N2 is completely activated in a side-on adsorption configuration on the hollow site of Fe4/GaS, where both degenerate N2–π* orbitals are properly hybridized to the frontier orbitals of the Fe4 cluster, as proven by fragment orbital analysis. This work proposes an efficient strategy for N2 activation, and also provides a valid design guideline for further research.

Highly efficient bifunctional electrocatalysts towards sluggish oxygen reduction and evolution reactions (ORR and OER) are of great significance for cathode catalysis of rechargeable metal–air batteries. Herein, we report a one-pot pyrolysis strategy to construct binary transition metal oxide (TMO) interfaces on a nitrogen doped porous carbon framework (CN) for bifunctional oxygen reaction catalysis. The constructed Fe3O4/Co3O4 interfaces not only help promote the stabilization of Fe2+ ions, but also generate abundant oxygen vacancies on the surface of composite catalysts (Fe3O4/Co3O4-CN), which boost the intrinsic oxygen reaction activity. The Fe3O4/Co3O4-CN catalyst exhibits a bifunctional electrocatalytic performance with a significantly lowered potential difference (ΔE) of 0.68 V between the half-wave potential of the ORR (E1/2) and the potential of the OER at a current density of 10 mA cm−2 (Ej=10), rivaling the best performance of previously reported bifunctional TMO catalysts to the best of our knowledge. The rechargeable Zn–air battery with Fe3O4/Co3O4-CN as the cathode catalyst exhibits superior performance with an energy density of 1045.82 W h kgZn−1 and a peak power density of 105.7 mW cm−2, as well as excellent cycling stability (over 80 h at a current density of 10 mA cm−2), demonstrating our new bifunctional oxygen electrocatalyst as a promising candidate for practical energy storage applications.

For reliable downstream molecular analysis, it is crucially important to recover circulating tumor cells (CTCs) from clinical blood samples with high purity and viability. Herein, magnetic nanoparticles coated with an antifouling hydrogel layer based on the polymerization method were developed to realize cell-friendly and efficient CTC capture and recovery. Particularly, the hydrogel layer was fabricated by zwitterionic sulfobetaine methacrylate (SBMA) and methacrylic acid (MAA) cross-linked with N,N-bis(acryloyl)cystamine (BACy), which could not only resist nonspecific adhesion but also gently recover the captured cells by glutathione (GSH) responsiveness. Moreover, the anti-epithelial cell adhesion molecule (anti-EpCAM) antibody was modified onto the surface of the hydrogel to provide high specificity for CTC capture. As a result, 96% of target cells were captured in the mimic clinical blood samples with 5-100 CTCs per mL in 25 min of incubation time. After the GSH treatment, about 96% of the obtained cells were recovered with good viability. Notably, the hydrogel-coated magnetic nanoparticles were also usefully applied to isolate CTCs from the blood samples of cancer patients. The favorable results indicate that the hydrogel-modified magnetic nanoparticles may have a promising opportunity to capture and recover CTCs for subsequent research.

It is of great importance to develop efficient and low-cost oxygen evolution reaction (OER) electrocatalysts for electrochemical water splitting. Herein, S doped NiCoVOx nanosheets grown on Ni-Foam (S-NiCoVOx/NF) with a modified electronic structure have been prepared through a facile one-step hydrothermal method. The as-prepared S4.06-NiCoVOx/NF exhibits outstanding OER activity with low overpotentials of 248 mV and 289 mV to deliver current densities of 10 mA cm−2 and 100 mA cm−2, respectively, and a small Tafel slope of 46.2 mV dec−1 in 1.0 M KOH electrolyte. These values are much lower than those obtained for most of the recently reported non-noble metal-based electrocatalysts under similar experimental conditions. This study provides a simple approach to rational design of efficient and cost-effective OER electrocatalysts for practical application of electrochemical water splitting.

The isolation of specific and sensitive circulating tumor cells (CTCs) is significant for applying them in cancer diagnosis and monitoring. In this work, dual aptamer-modified poly(lactic-co-glycolic acid) (PLGA) nanofiber-based microfluidic devices were fabricated to achieve the highly efficient capture and specific release of epithelial and mesenchymal CTCs of ovarian cancer. Dual aptamer targeting epithelial cell adhesion molecules (EpCAM) and N-cadherin proteins to improve the capture sensitivity, bovine serum albumin (BSA) to guarantee the capture purity and the nanofibers to increase the capture efficiency via synchronously and effectively capturing the epithelial and mesenchymal CTCs with good capture specificity and sensitivity from blood samples were used. We used the target cells including the ovarian cancer A2780 cells (N-cadherin-high, EpCAM-low) and OVCAR-3 cells (EpCAM-high, N-cadherin-low) to test the devices, which exhibited good capture efficiency (91% for A2780 cells, 89% for OVCAR-3 cells), release efficiency (95% for A2780 cells, 88% for OVCAR-3 cells), and sensitivity for rare cells (92% for A2780 cells, 88% for OVCAR-3 cells). Finally, the clinical blood samples of ovarian cancer patients were detected by the PLGA nanofiber-based microfluidic device, and 1 to 13 CTCs were successfully confirmed to be captured with the help of immunofluorescence staining identification. The results exhibited that the dual aptamer-modified PLGA nanofiber-based microfluidic device used as a tool for CTC capture has the potential for clinical application to guide the diagnosis, treatment, and prognosis of ovarian cancer patients.

One of the key challenges with atomic catalysts (single, double, and triple atom catalysts) is the relatively low loading of active materials, resulting in the low mass or volume activity of catalysts, which hinders their rapid development in the field of catalysis. Herein, using density functional theory (DFT), we explore a series of atomic catalysts with heterostructured substrate, graphdiyne and graphene (GDY/Gra), for the nitrogen reduction reaction (NRR). The theoretical mass loading of active metal atoms can exceed 35.0 wt% in the triple atom catalyst (TAC), which could be reached through the optimal substrate and suitable precursors in experiments. Among the designed atomic catalysts, Fe3-GDY/Gra with a theoretical mass loading of 35.8 wt% shows outstanding catalytic activity for the electrocatalytic NRR with a potential of −0.26 V vs. the reversible hydrogen electrode (RHE). Moreover, the proposed TACs show better catalytic activity for the NRR than single atom catalysts (SACs) and double atom catalysts (DACs) due to the unique properties of M3 (M = Mn, Fe, Co, and Ni) active sites, which provide more electrons for activating N2, but also have a weak adsorption to more easily release products. These findings provide a new strategy for designing atomic catalysts with high loading, high stability, and high activity.

Analysis of circulating tumor cells (CTCs) can provide significant clinical information for tumors, which has proven to be helpful for cancer diagnosis, prognosis monitoring, treatment efficacy, and personalized therapy. However, CTCs are an extremely rare cell population, which challenges the isolation of CTCs from patient blood. Over the last few decades, many strategies for CTC detection have been developed based on the physical and biological properties of CTCs. Among them, nanostructured interfaces have been widely applied as CTC detection platforms to overcome the current limitations associated with CTC capture. Furthermore, aptamers have attracted significant attention in the detection of CTCs due to their advantages, including good affinity, low cost, easy modification, excellent stability, and low immunogenicity. In addition, effective and nondestructive release of CTCs can be achieved by aptamer-mediated methods that are used under mild conditions. Herein, we review some progress in the detection and release of CTCs through aptamer-functionalized nanostructured interfaces.

AuPd nanoparticles with ultrafine sizes and good dispersion are successfully anchored on amine-functionalized monochlorotriazinyl β-cyclodextrin, and exhibit remarkable catalytic activity for hydrogen evolution from formic acid, affording an unprecedented initial turnover frequency of 7352 mol H2 per mol catalyst h−1 without any additives.

Circulating tumor cells (CTCs) have been considered as a significant biomarker for cancer metastasis and relapse. Effective detection of CTCs will play an important role in early cancer diagnosis, prognosis, progress monitoring, and personalized therapy. In this work, we developed a polystyrene (PS) nanosphere substrate to capture CTCs from whole blood samples. Bovine serum albumin (BSA), as an antifouling molecule, and folic acid, as a recognizing agent, were modified onto the surface of PS nanospheres via self-polymerization of dopamine. 8 HeLa cells could be captured when 10 cells were spiked into 1 mL of the whole blood sample. Then, the captured target cells were further proliferated through an in situ culture strategy on the polystyrene (PS) nanosphere substrate, and nearly 80 HeLa cells were obtained from 1 captured cell after 7 days of in situ culture, revealing the potential application for CTC isolation and proliferation.

Correction for ‘Enhanced performance of porous forward osmosis (FO) membrane in the treatment of oily wastewater containing HPAM by the incorporation of palygorskite’ by Qianwen Zhang et al., RSC Adv., 2021, 11, 22439–22449, DOI: 10.1039/D1RA02858H.

To deliver siRNA efficiently, prevailing conventional lipid or polymer encapsulation often needs multi-step compounding methods, which may inevitably introduce cationic or other components and may lead to cytotoxicity or an immune response. Herein, we present a novel enzymatic synthetic approach to produce tumor-targetable RNAi nanoflowers. The RNAi nanoflowers are mainly composed of multiple tandem copies of siRNA precursors by rolling circle transcription (RCT), and produce large amounts of siRNA to silence Bcl-2 gene expression after cellular uptake, which can overcome the problem of low loading capacity. In particular, the RNAi microspheres (RNAi-MS) were condensed into nanosized complexes (RNAi nanospheres, RNAi-NS) by cholesterol-modified DNA strands without the assistance of polycationic agents. RNAi-NS are entirely composed of nucleic acid, giving them lower cytotoxicity and immunogenicity, which can be caused by synthetic polycationic reagents. In addition, the RNAi nanoflowers can also integrate DNA aptamers that bind specifically to target membrane proteins for cell-targeting. Therefore, thousands of copies of siRNA will be delivered to cells specifically, and this RNAi nanoflower system will have great potential for siRNA delivery and biomedical applications.

Herein, we fabricated efficient MR imaging probes by incorporating gadolinium oxide nanoparticles (Gd2O3) and gadolinium hybrid nanoparticles (GH) within RBCs. The Gd2O3 and GH encapsulated in the RBCs exhibited high relaxation rates and revealed high sensitivity for T1 MR imaging.

We report a specific light-up fluorescent probe for i-motif DNA for the first time. Compared with the previously reported probes, neutral red could selectively interact with an i-motif and show a significant increase in its fluorescence. This feature makes it advantageous for designing label-free fluorescent sensing systems.

An N719 dye labeled short DNA chain is introduced onto the surface of a TiO2 photoelectrode by hybridizing with a pre-immobilized thrombin aptamer to enhance the photocurrent response. After incubating with thrombin, both the dye labeled chain releasing from the photoelectrode and the bound thrombin blocking the electron transfer resulted in a decreased photocurrent.

Interestingly, the glutathione capped Au-nanoclusters presented here showed a unique optical performance compared with their homological AuNPs with larger size. The luminescence intensity of the AuNCs could be enhanced due to the formation of aggregates. The AuNCs were then employed as a visual probe for the detection of Pb2+ based on the aggregation-induced emission enhancement (AIEE) property of the AuNCs. When the luminous glutathione capped AuNCs probes encountered Pb2+ ions, they rapidly formed aggregates through GSH–Pb2+ interaction in 1 minute, resulting in an enhanced luminescence intensity. The enhanced luminescence intensities showed a linear dependence on the concentrations of Pb2+ with satisfactory selectivity towards 12 kinds of divalent metal ions. More importantly, the probe can also be used for on-site testing to inspect Pb2+ contamination by using a portable UV flashlight.

AuPd-CeO2 nanocomposites directly nucleated and grown on nitrogen-doped reduced graphene oxide, exhibit excellent catalytic activity and 100% hydrogen selectivity toward formic acid decomposition for hydrogen generation without any additives at room temperature.

Ultrafine and well dispersed CoAuPd nanoparticles grown on a DNA-reduced-graphene-oxide (DNA-rGO) composite have been successfully synthesized using a DNA-directed method. The resultant CoAuPd/DNA-rGO composite exhibits high activity and 100% H2 selectivity toward the dehydrogenation of formic acid without any additive at 298 K.

Amorphous Ni0.9Pt0.1/Ce2O3 nanoparticles with low noble-metal content have been facilely synthesized by a co-reduction route within 10 min at room temperature under ambient atmosphere. The resultant Ni0.9Pt0.1/Ce2O3 nanoparticles were successfully applied as a highly efficient catalyst for rapid and complete conversion of hydrous hydrazine. A high initial turnover frequency value of 28.1 h−1 for Ni0.9Pt0.1/Ce2O3 nanoparticles is achieved with 100% H2 selectivity at 298 K. Moreover, the amorphous Ni0.9Pt0.1/Ce2O3 catalyst obtained due to the addition of Ce2O3 demonstrates much better activity and much lower activation energy than that of the crystalline Ni0.9Pt0.1. The development of the improved performance and low-cost catalyst is a promising step towards the application of hydrous hydrazine as a hydrogen storage material.

Here we report a green and facile strategy for the direct nucleation and growth of ultrafine (1.8 nm) and well dispersed Au@Pd core–shell nanoclusters on nitrogen-doped mildly reduced graphene oxide (Au@Pd/N–mrGO) without any surfactant and additional reducing agent. During the synthesis, N–mrGO acts as both the reducing agent and support by taking advantage of its moderate reducing and high dispersing capacities. Unexpectedly, the as-prepared Au@Pd/N–mrGO hybrid exhibits much greater activity than its alloy or monometallic counterparts toward hydrogen generation from formic acid aqueous solution without using any additive at room temperature.

Ag0.1Pd0.9 nanoparticles assembled on reduced graphene oxide are synthesized by a facile co-reduction route. The resultant AgPd nanoparticles/reduced graphene oxide exert 100% H2 selectivity and exceedingly high activity toward the complete decomposition of formic acid at room temperature under ambient conditions.

A general and energy-efficient strategy has been successfully applied for synthesis of a graphene–CuCo nanohybrid, which leads to the highest catalytic activity of Cu-based catalysts up to now toward the dehydrogenation of ammonia borane, and also the excellent activity for electrochemical hydrogen evolution reaction. Moreover, this general method can be easily extended to facile preparation of other graphene–metal systems.