Composites of (NH2)-MIL-53(Al) and CBB as bifunctional electrocatalysts for overall electrochemical water splitting in all pH solutions.

Electrochemical water splitting is one of the most active areas of energy research, yet the benchmark electrocatalysts used for this area are based on expensive noble metals and transition metals, thus mainly reactions in alkaline solution. MOFs and halide perovskite are novel electrochemical catalysts but unstable in water basically. Here we report a study on composites of (NH2)-MIL-53(Al) MOFs and CBB halide perovskite (Cs3Bi2Br9), which exhibit obvious activity for overall electrochemical water splitting for long-term stability with little deactivation after 10 h in all pH solutions.

A Nano-Electroporation-DNA Tensioner Platform Enhances Intracellular Delivery and Mechanical Analysis Toward Rapid Drug Assessment.

In vitro, drug assessment holds tremendous potential to success in novel drug development and precision medicine. Traditional techniques for drug assessment, however, face remarkable challenges to achieve high speed, as limited by incubation-based drug delivery (>several hours) and cell viability measurements (>1 d), which significantly compromise the efficacy in clinical trials. In this work, a nano-electroporation-DNA tensioner platform is reported that shortens the time of drug delivery to less than 3 s, and that of cellular mechanical force analysis to 30 min. The platform adopts a nanochannel structure to localize a safe electric field for cell perforation, while enhancing delivery speed by 103 times for intracellular delivery, as compared to molecular diffusion in coculture methods. The platform is further equipped with a DNA tensioner to detect cellular mechanical force for quantifying cell viability after drug treatment. Systematic head-to-head comparison, by analyzing FDA (food and drug administration)-approved drugs (paclitaxel, doxorubicin), demonstrated the platform with high speed, efficiency, and safety, showing a simple yet powerful tool for clinical drug screening and development.

Metal Ion-controlled Growth of Different Metal-Organic Framework Micro/nanostructures for Enhanced Supercapacitor Performance.

We report a metal ion-modulated effective strategy to achieve different metal-organic framework (MOF) micro/nanostructures using different metal precursors like CoCl2 ⋅ 6H2 O, CoCl2 ⋅ 6H2 O and NiCl2 ⋅ 6H2 O, and NiCl2 ⋅ 6H2 O with pyridine-3,5-dicarboxylate (3,5-pdc). The structural characterizations confirm that different morphological structures, hollow microsphere, hierarchical nanoflower, and solid nanosphere are for Co-(3,5-pdc), Co0.19 Ni0.81 -(3,5-pdc), and Ni-(3,5-pdc), respectively. These different MOF micro/nanostructures correlate with the coordination ability of Co and Ni with 3,5-pdc. Benefitting from the synergistic effect of the alloying metal nodes of Co and Ni producing rapid and rich redox reactions and the hierarchical nanoflower with higher surface area enabling excellent ion kinetics, the Co0.19 Ni0.81 -(3,5-pdc) exhibits higher specific capacitance of 515 F g-1 /273 C g-1 at 0.5 A g-1 than that of Ni-(3,5-pdc) (290 F g-1 /153.7 C g-1 ) and Co-(3,5-pdc) (132 F g-1 /67 C g-1 ), good rate capability and cycling stability. Moreover, the asymmetric supercapacitor device (Co0.19 Ni0.81 -(3,5-pdc)//AC) assembled from Co0.19 Ni0.81 -(3,5-pdc) and activated carbon (AC) achieves a maximum energy density of 42.6 Wh kg-1 at a power density of 277.3 W kg-1 .

Sensitive, rapid detection of NCOA4-m6A towards precisely quantifying radiation dosage on a Cas13a-Microdroplet platform.

Precise quantification of low-dose ionizing radiation is of great significance in protecting people from damage caused by clinical radiotherapy or environmental radiation. Traditional techniques for detecting radiation, however, remain extreme challenges to achieve high sensitivity and speed in quantifying radiation dosage. In this work, we report a Cas13a-Microdroplet platform that enables sensitive detection of ultra-low doses of radiation (0.5 Gy vs. 1 Gy traditional) within 1 h. The micro-platform adopts an ideal, specific radiation-sensitive marker, m6A on NCOA4 gene (NCOA4-m6A) that was first reported in our recent work. Microfluidics of the platform generate uniform microdroplets that encapsulate a CRISPR/Cas13a detection system and NCOA4-m6A target from the whole RNA extraction, achieving 10-fold enhancement in sensitivity and significantly reduced limit of detection (LOD). Systematic mouse models and clinical patient samples demonstrated its superior sensitivity and LOD (0.5 Gy) than traditional qPCR, which show wide potentials in radiation tracking and damage protection.

Post-synthetic atomically precise single-CuII sites in a thiacalix[4]arene-supported octahedral Na@Co24 cluster: the Cu-Co synergistic effect for selective photocatalytic conversion of CO2 to CO.

A thiacalix[4]arene-supported octahedral Na@Co24 cluster has been fabricated by the modular assembly of six Co4-(TC4A) polynuclear secondary building units (PSBUs) and eight 2,4,6-PTC linkers. The post-modification of Na@Co24 by ion exchange of Na+ with Cu2+ on the surface of the octahedron afforded a structurally well-defined Cu@Co24 cluster. The obtained Cu@Co24 cluster achieved improved visible-light absorption and selective photoreduction of CO2 to CO due to the Cu-Co synergistic effect.

Synergistic effect of Co/Ni bimetallic metal-organic nanostructures for enhanced electrochemical energy storage.

Introducing a secondary metal ion is an effective strategy to significantly enhance the electrochemical performance of monometallic metal-organic frameworks (MOFs). Herein, we synthesize a series of cobalt-nickel bimetallic MOFs (Co/Ni-MOFs) by the Co2+ substitution into Ni-MOF ({Ni3(OH)2(tdc)2(H2O)4}n, H2tdc = 2,5-thiophenedicarboxylic acid). The Co/Ni-MOF-2:1 with optimal Co/Ni ratio possesses improved electrical conductivity, intrinsic reactivity, and stability. Compared with the monometallic Ni-MOF, the bimetallic Co/Ni-MOF-2:1 with nanowire morphology achieves a higher specific capacitance (610 F g-1 at a current density of 0.5 A g-1), a better rate capacity (88 % capacitance retention at 5 A g-1) and cycling performance (72 % retention after 5000 cycles). Moreover, the asymmetric supercapacitor constructed with Co/Ni-MOF-2:1 and activated carbon exhibits a high specific capacitance (228 F g-1 at 0.5 A g-1) and excellent cycling stability (95.5 % of capacitance retention after 5000 circulations at 5 A g-1).

In Situ Generation of NiCoP Nanoparticles on a Bimetal-Organic Framework for High-Performance Supercapacitors.

The rational exploration of hybrid materials with well-defined compositions and structures/morphologies is essential for achieving high-performance electrodes for supercapacitors. Here, in situ dispersion and anchoring of NiCoP nanoparticles (NPs) on a bimetal-organic framework (Co1Ni2-MOF) by a controllable partial phosphorization approach are reported. The phosphating temperature and time significantly affect the specific capacitance of NiCoP/Co1Ni2-MOF-X-Y (where X and Y represent the phosphating temperature and time, respectively). Co1Ni2-MOF provides anchoring sites for confining NiCoP NPs, effectively improving the stability of NiCoP NPs. Highly dispersed NiCoP NPs facilitate OH- adsorption, boosting the redox reaction kinetics. NiCoP/Co1Ni2-MOF-350-2 with optimized phosphating conditions exhibits a high specific capacitance of 525 F g-1 at 0.5 A g-1, which is superior to that of the precursor of Co1Ni2-MOF. Moreover, a hybrid supercapacitor constructed with NiCoP/Co1Ni2-MOF-350-2 and activated carbon shows a high specific capacitance and outstanding long-term stability.

High-Throughput DNA Tensioner Platform for Interrogating Mechanical Heterogeneity of Single Living Cells.

Cell mechanical forces play fundamental roles in regulating cellular responses to environmental stimulations. The shortcomings of conventional methods, including force resolution and cellular throughput, make them less accessible to mechanical heterogeneity at the single-cell level. Here, a DNA tensioner platform is introduced with high throughput (>10 000 cells per chip) and pN-level resolution. A microfluidic-based cell array is trapped on "hairpin-structured" DNA tensioners that enable transformation of the mechanical information of living cells into fluorescence signals. By using the platform, one can identify enhanced mechanical forces of drug-resistant cells as compared to their drug-sensitive counterparts, and mechanical differences between metastatic tumor cells in pleural effusion and nonmetastatic histiocytes. Further genetic analysis traces two genes, VEGFA and MINK1, that may play deterministic roles in regulating mechanical heterogeneities. In view of the ubiquity of cells' mechanical forces in the extracellular microenvironment (ECM), this platform shows wide potential to establish links of cellular mechanical heterogeneity to genetic heterogeneity.

A coordination cage hosting ultrafine and highly catalytically active gold nanoparticles.

Ultrafine metal nanoparticles (MNPs) with size <2 nm are of great interest due to their superior catalytic capabilities. Herein, we report the size-controlled synthesis of gold nanoparticles (Au NPs) by using a thiacalixarene-based coordination cage CIAC-108 as a confined host or stabilizer. The Au NPs encapsulated within the cavity of CIAC-108 (Au@CIAC-108) show smaller size (∼1.3 nm) than the ones (∼4.7 nm) anchored on the surface of CIAC-108 (Au/CIAC-108). The cage-embedded Au NPs can be used as a homogeneous catalyst in a mixture of methanol and dichloromethane while as a heterogeneous catalyst in methanol. The homogeneous catalyst Au@CIAC-108-homo exhibits significantly enhanced catalytic activities toward nitroarene reduction and organic dye decomposition, as compared with its larger counterpart Au/CIAC-108-homo and its heterogeneous counterpart Au@CIAC-108-hetero. More importantly, the as-prepared Au@CIAC-108-homo possesses remarkable stability and durability.

Synthesis of truncated octahedral zinc-doped manganese hexacyanoferrates and low-temperature calcination activation for lithium-ion battery.

Owing to their open three-dimensional framework structure, Prussian blue analogues (PBAs) have attracted increasing interest as anode materials for future lithium-ion batteries (LIBs). However, some disadvantages, such as inferior stability and short cycle life, hinder its utilization significantly. Hence, we develop a simple method to prepare a unique truncated octahedral ZnMnFe-PBA with exposed {111} crystal facets. The doping of Zn into Mn-based PBA enhances structural stability and improves the electronic conductivity. Meanwhile, low-temperature calcination not only improves the electrochemical activity but also preserves the porosity to enable mass transfer. When the ratio of Mn:Zn is 90:10 and the calcination temperature is 100 °C, sample Z10-100 displays high capacity and excellent cycle life (∼510.6 mA h g-1 at 0.1 A g-1, 168.9 mA h g-1 after 5000 cycles at 1.0 A g-1 with 99.9% capacity retention). The significant improvements in cycle stability and cycle life are attributable to transition metal ion doping and effective low-temperature calcination activation, which provide a facile approach for the synthesis of low-cost and efficient electrode materials.

From Co-MOF to CoNi-MOF to Ni-MOF: A Facile Synthesis of 1D Micro-/Nanomaterials.

Controlling the growth of metal-organic frameworks (MOFs) at the micro-/nanoscopic scale will result in new physical properties and novel functions into the materials without changing the chemical identities and the characteristic features of the MOFs themselves. Herein, we report a facile approach to synthesize a series of MOFs [Co-MOF, CoxNiy-MOFs (x and y represent the molar ratio of Co2+ and Ni2+ and x/y = 1:1, 1:5, 1:10, 1:15, and 1:20), and Ni-MOF] with a one-dimensional micro-/nanoscaled rod-like architecture. From Co-MOF to CoxNiy-MOFs to Ni-MOF, the diameters of the rods turn to be spindly with the increase of Ni2+ content which will facilitate the supercapacitor performances. Interestingly, Co1Ni20-MOF exhibits a highest specific capacity of 597 F g-1 at 0.5 A g-1 and excellent cycle performance (retained 93.59% after 4000 cycles) among these MOF materials owing to its micro-/nanorod structure with a smaller diameter and the synergy effect between the optimum molar ratio of Co2+ and Ni2+.

Co9 S8 @CN Composites Obtained from Thiacalix[4]arene-Based Coordination Polymers for Supercapacitor Applications.

Metal sulfides have been recognized as promising electrodes for electrochemical energy storage owing to their remarkable electrochemical properties. Here, we demonstrate the preparation of Co9 S8 nanoparticles anchored on a carbon matrix (denoted as Co9 S8 -X@CN (X=1, 2)) from precursor sources, two 1D infinite coordination polymers 1 and 2. The two polymers were assembled by linking Co4 -TC4A secondary building blocks (SBUs) with ligands L1 and L2 , respectively (H4 TC4A=p-tert-butylthiacalix[4]arene, L1 =1,4-bis(2H-tetrazol-5-yl)benzene, L2 =1,3-bis(2H-tetrazol-5-yl)benzene). The composites obtained from 1D polymers showed different morphologies, that is, the Co9 S8 nanoparticles of Co9 S8 -1@CN are octahedral with a size of ca. 140 nm, while the lamellar Co9 S8 nanoparticles in Co9 S8 -2@CN possess different sizes (50-150 nm). The Co9 S8 -2@CN immobilized on nickel foam (Co9 S8 -2@CN/NF) show better supercapacitive performance than that of Co9 S8 -1@CN. Co9 S8 -2@CN showed exceptionally high activities, combining higher specific capacitances (445.2 F g-1 at 2 A g-1 and 393.9 F g-1 and 5 A g-1 ), rate capacity (94.5% retention at 2 A g-1 ), and long-term stability (79.2% retention at 5 A g-1 over 1000 cycles). The smaller size and larger BET surface area of Co9 S8 -2@CN nanoparticles can improve the electrical conductivity and provide facile pathways for charge transport, thus leading to conspicuous electrochemical performance of Co9 S8 -2@CN compared with its Co9 S8 -1@CN counterpart.

Single Living Cell Analysis Nanoplatform for High-Throughput Interrogation of Gene Mutation and Cellular Behavior.

The genetic heterogeneities in cancer cells pose challenges to achieving precise drug treatment in a widely applicable manner. Most single-cell gene analysis methods rely on cell lysis for gene extraction and identification, showing limited capacity to provide the correlation of genetic properties and real-time cellular behaviors. Here, we report a single living cell analysis nanoplatform that enables interrogating gene properties and drug resistance in millions of single cells. We designed a Domino-probe to identify intracellular target RNAs while releasing 10-fold amplified fluorescence signals. An on-chip addressable microwell-nanopore array was developed for enhanced electro-delivery of the Domino-probe and in situ observation of cell behaviors. The proof-of-concept of the system was validated in primary lung cancer cell samples, revealing the positive-correlation of the ratio of EGFR mutant cells with their drug susceptibilities. This platform provides a high-throughput yet precise tool for exploring the relationship between intracellular genes and cell behaviors at the single-cell level.

Thiacalix[4]arene-supported molecular clusters for catalytic applications.

Thiacalixarenes are intriguing ligands that have attracted sustained interest because of their changeable conformations and excellent coordination ability. Thiacalix[4]arene analogues, which can bind metal ions to form modular second building units, are capable of constructing molecular-based functional materials with defined structures and various applications via directional coordination assembly. Due to rich metal-sulfur bonds, thiacalix[4]arene-based molecular clusters also exhibit diverse properties compared to other clusters. In particular, the combination of thiacalixarenes with currently popular molecular architectures, such as high-nuclearity clusters and coordination cages, has shown special catalytic performances. In this perspective, the latest advances in catalytic applications of thiacalix[4]arene-based molecular clusters, including molecular clusters themselves as catalysts and coordination cages serving as reaction vessels encapsulating metal nano-components for catalysis, are highlighted.

Nanosensors for single cell mechanical interrogation.

The occurrence and development of many diseases are accompanied and sometimes dictated by the destruction of biomechanical homeostasis. For instance, cancer cells and normal cells show different cellular mechanical forces phenotypes, as the proliferation and invasion ability of cancer cells is often related to the changes in mechanical force in the tumor. With single cell analysis, variations in mechanics within a cell population can be detected and analyzed, opening new dimensions in the study of cancer. Nanosensor design for interrogation of cell mechanics is an interdisciplinary area bridging over cell biology, mechanics, and micro/nanotechnology. In this tutorial review, we give insight into the background and technical innovation of currently available methods for mechanical analysis of cells. First, we discuss the mechanism of mechanical changes in the development and progression of cancer that shows the feasibility of mechanical sensors in cancer cell detection. Next, we summarize the principle, progress, and essential problems of common technologies for cell force measurement, including single molecule force spectroscopy and elastic substrate-sensors. Following that, we discuss novel micro and nano-scale mechanical sensors and their applications in single cell level biological analysis. At last, we elaborate on the remaining issues and trends of the cellular mechanical sensors.

Assembly of thiacalix[4]arene-supported high-nuclearity Cd24 cluster with enhanced photocatalytic activity.

A high-nuclearity nanoscale Cd24 cluster has been hydrothermally synthesized by assembly of Cd4-TC4A (H4TC4A = p-tert-butylthiacalix[4]arene) second building units (SBUs) and in situ generated peroxy(mono)phosphate PO53- groups and peroxyphenoxide groups of TC4A. The cluster was structurally characterized by single crystal X-ray diffractions. Photocatalytic studies revealed that the highest nuclearity Cd,S-co-rich Cd24 cluster exhibits enhanced photocatalytic water splitting activities compared to the sandwich Cd4(TC4A)2 (Cd4) cluster under the same conditions in the absence of a co-catalyst. The nanostructure of Cd24 incorporated both peroxyphosphate and peroxyphenoxide groups, which increased the metal coordination numbers to give more labile Cd-O/S bonds and is believed to be the key feature that enables the significant photocatalytic water splitting activities.

A 2D metal-thiacalix[4]arene porous coordination polymer with 1D channels: gas absorption/separation and frequency response.

A 2D layered structure {[Co4(TC4A)Cl](L)2][(CH3CH2)4N]}n (+solvent)(1) has been solvothermally synthesized by assembly of Co4-TC4A (H4TC4A = p-tert-butylthiacalix[4]arene) subunits and L (H2L = 4-(1H-tetrazol-5-yl)benzoic acid) ligands. The layers arranged in an edge-to-edge (AAAA) manner, which represented the only example of 2D porous coordination polymers (PCPs) with 1D uniform channels of metal-thiacalix[4]arene. The activated PCP 1 exhibited high selectivity for C3H8/C2H6, C3H6/C2H4, and C3H8/C2H4, which makes it a competitive porous material for C3/C2 alkane and/or olefin separations. Frequency response investigations for C3H8 and C2H6 indicated that the 1D channels and inter-layer voids of the activated crystalline samples are primarily responsible for the observed gas adsorption and separation performances.

Calixarene-Based {Ni18} Coordination Wheel: Highly Efficient Electrocatalyst for the Glucose Oxidation and Template for the Homogenous Cluster Fabrication.

Catalyst plays a very important role in the exploration of new energy. To obtain a highly efficient electrocatalyst for the glucose oxidation and tiny metal nanocluster catalysts, a calixarene-based {Ni18} coordination wheel with sulfur atoms on the cavity surface was designed, synthesized, and used as the porous template. Contributing from the active sites of nickel cations, the as-synthesized coordination wheels can efficiently catalyze the electrochemical oxidation of glucose with the onset and peak potentials of 0.3 and 0.46 V in alkaline medium, and the catalysis does not depend on the atmosphere (N2, air, or O2), which indicates that the coordination wheel will be a promising electrocatalyst candidate for the compartmentless glucose-air fuel cell. Meanwhile, benefiting from its confined cavity and inner sulfur surface, such a coordination wheel can serve as a general template for the fabrication and encapsulation of tiny metal nanoclusters of Au, Pd, Ir, Ru, Rh, Pt, and AuPd. In electrochemical examinations, the bimetallic AuPd clusters confined in the coordination wheel show higher current density than commercial Pt/C toward hydrogen evolution reaction (HER). The present study shows that the designed coordination wheel can be used as not only a type of novel catalyst itself but also a class of templates for metal cluster catalysts.

A metal-calixarene coordination nanotube with 5-(pyrimidin-5-yl)isophthalic acid.

A metal-organic nanotube (MONT) was assembled by bridging the truncated metal-calixarene octahedra with coordinating water molecules. Remarkably, the tubular compound exhibited a much higher sorption capacity for C2H6 and C3H8 than for CH4, and hence represents a promising material for separating these gases. The addition of a little NiSO4 into the reaction system led to the formation of a 2D metal-calixarene network.

Ultrafine Pt Nanoclusters Confined in a Calixarene-Based {Ni24} Coordination Cage for High-Efficient Hydrogen Evolution Reaction.

To obtain stable and ultrafine Pt nanoclusters, a trigonal prismatic coordination cage with the sulfur atoms on the edges was solvothermally synthesized to confine them. In the structure of {Ni24(TC4A-SO2)6(TDC)12 (H2O)6} (H4TC4A-SO2 = p-tert-butylsulfonylcalix[4]arene; H2TDC = 2,5-thiophenedicarboxylic acid), three Ni4-(TC4A-SO2) SBUs are bridged by three TDC ligands into a triangle and two such triangles are pillared by three pairs of TDC ligands to form a trigonal prism. The cage cavity has 12 sulfur atoms on the surface. Because of the porous structure and strong covalent interaction between metal and sulfur, ultrafine Pt nanoclusters composed of less than ∼18 Pt atoms can be facilely confined in the present trigonal prismatic cage (Pt@CIAC-121). The as-synthesized Pt NCs exhibit higher electrocatalytic activity than commercial Pt/C toward hydrogen evolution reaction.