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Although several separation membranes for the purification of dye-containing oily wastewater have been reported, achieving continuous one-step separation and photodegradation of complex oil/water effluents containing dyes is still a significant challenge. In previous studies, the purification of oil/water mixtures has typically involved a two-step process involving the initial separation of oil/water mixtures followed by the subsequent photodegradation of organic dyes. This is because one-step purification requires the membrane to concurrently possess an excellent separation efficiency and photodegradation ability to ensure efficient degradation of dyes as they rapidly pass through the separation membrane. Herein, we propose a photothermally responsive poly-(N-isopropylacrylamide)-MXene/polyacrylonitrile-poly-(N-isopropylacrylamide) nanofibrous hydrogel membrane (PNIPAm-MXene/PAN-PNIPAm, PMPP membrane). The PMPP membrane is composed of a PNIPAm-MXene hydrogel bonded to the surface of a PAN-PNIPAm nanofibrous membrane. The PNIPAm-MXene hydrogel layer imparts excellent photothermally responsive wettability, photodegradation activity, and antifouling properties to the membrane. The PAN-PNIPAm nanofibrous membrane provides a porous structure that ensures the highly efficient separation of complex oil/water mixtures. The PMPP membrane achieves simultaneous one-step separation and photodegradation of complex oil/water effluents under light irradiation, particularly in the case of multiphase heavy oil/water/light oil mixtures containing both oily and water-soluble organic dyes and oil–water emulsions. The degradation and separation efficiencies of the PMPP membrane exceed 99.5%. Even after 20 cycles, the degradation rates of Sudan IV and methyl blue (MB) remain above 95.7 and 99.9%, respectively. [ABSTRACT FROM AUTHOR]

A study on C60 fullerenes and fullerene derivatives was conducted to investigate structures and aggregation behavior of a starlike ionomer, C60[(CH2)nSO3Na]6 with n=4 in water solutions. Small angle neutron scattering and small angle X-ray scattering techniques were employed in the study. Interparticle interactions between the aggregates of star ionomers were observed that proved to be much weaker and insensitive to the temperature change for the concentrations investigated. Other findings are discussed.

Online detection of methanol electro-oxidation reaction products [e.g., formaldehyde (HCHO)] by mass spectrometry (MS) is challenging, owing to the high salt content and extreme pH of the electrolyte solution as well as the difficulty in ionizing the reaction products. Herein we present an online ambient mass spectrometric approach for analyzing HCHO generated from methanol electro-oxidation, taking the advantage of high salt tolerance of desorption electrospray ionization mass spectrometry (DESI-MS). It was found that HCHO can be detected as PhNHNH=CH ( m/z 121) by DESI after online derivatization with PhNHNH. With this approach, the analysis of HCHO from methanol electro-oxidation by MS was carried out not only in acidic condition but also in alkaline media for the first time. Efficiencies of different electrodes for methanol oxidation at different pHs were also evaluated. Our results show that Au electrode produces more HCHO than Pt-based electrodes at alkaline pH, while the latter have higher yields at acidic solution. The presented methodology would be of great value for elucidating fuel cell reaction mechanisms and for screening ideal fuel cell electrode materials. [ABSTRACT FROM AUTHOR]

A study was conducted to examine the phase separation, coalescence and annihilation of liquid crystal textures during polymerization of wholly aromatic main-liquid crystalline polymer. Using a novel thin film polymerization method, it was observed that during the early stage of the polymerization, the liquid crystal domains generated have the disclination strength of +1. The dominant factor affecting the annihilation rate during this stage is the low viscosity characteristics at elevated temperatures.

We have developed an improved small-angle X-ray scattering (SAXS) model and analysis methodology to quantitatively evaluate the nanostructures of a blend system. This method has been applied to resolve the various structures of self-organized poly(3-hexylthiophene) /C61-butyric acid methyl ester (P31-IT/PCBM) thin active layer in a solar cell from the studies of both grazing-incidence small-angle X-ray scattering (GISAXS) and grazing-incidence X-ray diffraction (GIXRID). Tuning the various length scales of PCBM-related structures by a different annealing process can provide a flexible approach and better understanding to enhance the power conversion of the P3HT/PCBM solar cell. The quantitative structural characterization by this method includes (1) the mean size, volume fraction, and size distribution of aggregated PCBM clusters, (2) the specific interface area between PCBM and P3HT, (3) the local cluster agglomeration, and (4) the correlation length of the PCBM molecular network within the P3HT phase. The above terms are correlated well with the device performance. The various structural evolutions and transformations (growth and dissolution) between PCBM and P3HT with the variation of annealing history are demonstrated here. This work established a useful SAXS approach to present insight into the modeling of the morphology of P3HT/PCBM film. In situ GISAXS measurements were also conducted to provide informative details of thermal behavior and temporal evolution of PCBM-related structures during phase separation. The results of this investigation significantly extend the current knowledge of the relationship of bulk heterojunction morphology to device performance. [ABSTRACT FROM AUTHOR]

MOF-5-like crystals were studied by small-angle X-ray scattering (SAXS) to reveal, both quantitatively and qualitatively, their real structural details, including pore surface characteristics, pore shape, size distribution, specific surface area (SSA), spatial distribution, and pore-network structure. A combined SAXS and wide-angle X-ray scattering (WAXS) experiment was conducted to investigate the variation of the pore structure with the MOF-5 crystalline phase produced at different cooling rates. The SSA of the MOF-5 crystals synthesized herein spanned a broad range from ∼3100 to 800 m2/g. The real pore structures were divided into two regimes. In regime I the material consisted mainly of micropores of radius ∼8 Å as well as mesopores of radius 120-∼80 Å. The structure in regime II was a fractal network of aggregated mesopores with radius ≥32 Å as the monomer, reducing SSA and hydrogen uptake capacity at room temperature. The two regimes can be manipulated by controlling the synthesis parameters. The concurrent evolution of pore structure and crystalline phase during heating for solvent removal was also revealed by the in-situ SAXS/WAXS measurement. The understanding of the impact of the real pore structure on the properties is important to establish a favorable synthetic approach for markedly improving the hydrogen storage capacity of MOF-5. [ABSTRACT FROM AUTHOR]

The article presents a study regarding the uptake of room temperature hydrogen through bridged spillover. It mentions the problems in hydrogen storage and states that porous metal-organic frameworks (MOF) can be used for the storage. Hydrogen uptake depends upon imperfect lattice structure and pore network in MOF structure that can facilitate the spillover and enhance the hydrogen uptake at moderate pressures.

In pursuing high stability and power conversion efficiency for organic photovoltaics (OPVs), a sequential deposition (SD) approach to fabricate active layers with p-i-n structures (where p, i, and n represent the electron donor, mixed donor:acceptor, and electron acceptor regions, respectively, distinctively different from the bulk heterojunction (BHJ) structure) has emerged. Here, we present a novel approach that by incorporating two polymer donors, PBDBT-DTBT and PTQ-2F , and one small-molecule acceptor, BTP-3-EH-4Cl , into the active layer with sequential deposition, we formed a device with nanometer-scale twin p-i-n structured active layer. The twin p-i-n PBDBT-DTBT:PTQ-2F/BTP-3-EH-4Cl device involved first depositing a PBDBT-DTBT:PTQ-2F blend under layer and then a BTP-3-EH-4Cl top layer and exhibited an improved power conversion efficiency (PCE) value of 18.6%, as compared to the 16.4% for the control BHJ PBDBT-DTBT:PTQ-2F:BTP-3-EH-4Cl device or 16.6% for the single p-i-n PBDBT-DTBT/BTP-3-EH-4Cl device. The PCE enhancement resulted mainly from the twin p-i-n active layer's multiple nanoscale charge carrier pathways that contributed to an improved fill factor and faster photocurrent generation based on transient absorption studies. The PBDBT-DTBT:PTQ-2F/BTP-3-EH-4Cl film possessed a vertical twin p-i-n morphology that was revealed through secondary ion mass spectrometry and synchrotron grazing-incidence small-angle X-ray scattering analyses. The thermal stability ( T 80 ) at 85 °C of the twin p-i-n PBDBT-DTBT:PTQ-2F/BTP-3-EH-4Cl device surpassed that of the single p-i-n PBDBT-DTBT/BTP-3-EH-4Cl devices (906 vs 196 h). This approach of providing a twin p-i-n structure in the active layer can lead to substantial enhancements in both the PCE and stability of organic photovoltaics, laying a solid foundation for future commercialization of the organic photovoltaics technology.

Identification of diverse biomarkers in heterogenic circulating malignant cells (CMCs) such as circulating tumor cells (CTCs) and circulating tumor endothelial cells (CTECs) has crucial significance in tumor diagnosis. However, it remains a substantial challenge to achieve in situ detection of multiple miRNA markers in living cells in blood. Herein, we demonstrate that an aptamer/peptide-functionalized vector can deliver molecular beacons into targeted living CMCs in peripheral blood of patients for in situ detection of multiple cancer biomarkers, including miRNA-21 (miR-21) and miRNA-221 (miR-221). Based on miR-21 and miR-221 levels, heterogenic CMCs are identified for both nondistant metastatic and distant metastatic cancer patients. CMCs from nondistant metastatic and distant metastatic cancer patients exhibit similar miR-21 levels, while the miR-221 level in CMCs of the distant metastatic cancer patient is higher than that of the nondistant metastatic cancer patient. With the capability to realize precise probing of multiple intracellular biomarkers in living CMCs at the single-cell resolution, the nanoprobe can reveal the tumor heterogeneity and provide useful information for diagnosis and prognosis. The nanoprobe we developed would accelerate the progress toward noninvasive precise cancer diagnosis.

Achieving large-area organic photovoltaic (OPV) modules with reasonable cost and performance is an important step toward commercialization. In this work, solution-processed conventional and inverted OPV modules with an area of 216 cm 2 were fabricated by the blade coating method. Film uniformity was controlled by adjusting the fabrication parameters of the blade coating procedure. The influence of the concentration of the solutions of the interfacial materials on OPV module performance was investigated. For OPV modules based on the PM6:Y6 photoactive layer, a certificated power conversion efficiency (PCE) of 9.10% was achieved for the conventional OPV modules based on the TASiW-12 interfacial layer while a certificated PCE of 11.27% was achieved for the inverted OPV modules based on the polyethylenimine (PEI) interfacial layer. As for OPV modules based on a commercially available photoactive layer, PV-X Plus, a PCE of 8.52% was achieved in the inverted OPV modules. A halogen-free solvent, o -xylene, was used as the solvent for PV-X Plus, which makes the industrial production much more environmentally friendly.

Tumor hypoxia severely restrains the efficiency of irreversible O 2 -consumption photodynamic therapy. The deep hypoxia induced by photodynamic therapy can promote the level of hypoxia inducible factor 1α that participates in many tumor processes and eventually lead to poor therapeutic outcomes. Herein, a chemo-photodynamic antitumor strategy based on ultrathin graphitic carbon nitride nanosheets loaded with a hypoxia-targeting platinum(IV) prodrug is reported. Under low-intensity visible light irradiation, such integrated nanosheets effectively generate reactive oxygen species together with DNA binding platinum species to achieve enhanced antiproliferation efficacy by downregulating HIF-1α under hypoxic conditions.

Selective amplification of reactive oxygen species (ROS) generation in tumor cells has been recognized as an effective strategy for cancer therapy. However, an abnormal tumor metabolism, especially the mitochondrial glutaminolysis, could promote tumor cells to generate high levels of antioxidants (e.g., glutathione) to evade ROS-induced damage. Here, we developed a tumor-targeted nanoparticle (NP) platform for effective breast cancer therapy via combining inhibition of mitochondrial glutaminolysis and chemodynamic therapy (CDT). This NP platform is composed of bovine serum albumin (BSA), ferrocene, and purpurin. After surface decoration with a tumor-targeting aptamer and then intravenous administration, this NP platform could target tumor cells and release ferrocene to catalyze hydrogen peroxide (H 2 O 2 ) into the hydroxyl radical (·OH) for CDT. More importantly, purpurin could inhibit mitochondrial glutaminolysis to concurrently prevent the nutrient supply for tumor cells and disrupt intracellular redox homeostasis for enhanced CDT, ultimately leading to the combinational inhibition of tumor growth.

Immunotherapy has provided a promising strategy for the treatment of cancers. However, even in tumors with high antigen burdens, the systemic inhibition of the antigen presentation still greatly restricts the application of immunotherapy. Here, we construct a tumor protein-engineering system based on the functional tripeptide, Asp-Phe-Tyr (DFY), which can automatically collect and deliver immunogenetic tumor proteins from targeted cells to immune cells. Through a tyrosinase-catalyzed polymerization, the DFY tripeptide selectively accumulates in tyrosinase high-expressed melanoma cells. Then quinone-rich intermediates are covalently linked with tumor-specific proteins by Michael addition and form tumor protein-carried microfibers that could be engulfed by antigen-presenting cells and exhibited tumor antigenic properties for boosting immune effect. In melanoma cells with deficient antigen presentation, this system can successfully enrich and transport tumor antigen-containing proteins to immune cells. Furthermore, in the in vivo study on murine melanoma, the transdermal delivery of the DFY tripeptide suppressed the tumor growth and the postsurgery recurrence. Our findings provide an avenue for the regulation of the immune system on an organism by taking advantage of certain polymerization reactions by virtue of chemical biology.

To enhance the specificity and sensitivity of molecular beacons (MBs) in detecting mRNA in living tumor cells, we introduced an aptamer (AS1411) to the delivery system of MBs to form an aptamer-decorated nanoprobe (ANP), which was prepared through self-assembly between AS1411-conjugated carboxymethyl chitosan (ACMC) with protamine sulfate (PS)/CaCO 3 /MB cores. Owing to the specific binding of AS1411 to nucleolin, which is overexpressed in tumor cell membranes and nuclei, an AS1411-decorated MB-delivery system leads to dramatically increased cell uptake of MBs for probing survivin mRNA and thus induces strong intracellular fluorescence emission in targeted tumorous cells and cell nuclei. Furthermore, we demonstrate that ANP can efficiently detect survivin mRNA in mitochondria. In other words, the effective delivery of MBs ensures the precise detection of mRNA distribution in diverse organelles. In addition, we evaluated the efficiency of ANP in probing tumor cells in simulated blood as well as in peripheral blood from a healthy donor and found that the nanoprobe can specifically deliver MBs to tumor cells and identify tumor cells in blood. The targeting delivery system we constructed holds promising applications in precise detection of subcellular distribution of mRNA in living tumor cells as well as in fluorescence-guided cancer detection in liquid biopsy technology. This study provides a facile strategy to effectively improve the specificity and sensitivity of conventional molecular beacons.

Solution-processed organic photovoltaics (OPVs) based on bulk-heterojunctions have gained significant attention to alleviate the increasing demend of fossil fuel in the past two decades. OPVs combined of a wide bandgap polymer donor and a narrow bandgap nonfullerene acceptor show potential to achieve high performance. However, there are still two reasons to limit the OPVs performance. One, although this combination can expand from the ultraviolet to the near-infrared region, the overall external quantum efficiency of the device suffers low values. The other one is the low open-circuit voltage ( V OC ) of devices resulting from the relatively downshifted lowest unoccupied molecular orbital (LUMO) of the narrow bandgap. Herein, the approach to select and incorporate a versatile third component into the active layer is reported. A third component with a bandgap larger than that of the acceptor, and absorption spectra and LUMO levels lying within that of the donor and acceptor, is demonstrated to be effective to conquer these issues. As a result, the power conversion efficiencies (PCEs) are enhanced by the elevated short-circuit current and V OC ; the champion PCEs are 11.1% and 13.1% for PTB7-Th:IEICO-4F based and PBDB-T:Y1 based solar cells, respectively.

Limonene, a cyclic monoterpene, is widely used in food and cosmetics industries as well as in agriculture. In the work described herein, employing a systematic optimization strategy, we constructed an efficient platform for producing limonene via the heterologous mevalonate pathway in Escherichia coli. By site-directed mutation of EfMvaS and tuning the initial translation of EfMvaE and EfMvaSA110G through ribosome binding site engineering, the upstream module for overproducing mevalonate was obtained. Expression of MmMK with ScPMK, ScPMD, and ScIDI under FAB80 promoter resulted in an efficient midstream module to produce 181.73 mg/L of limonene. Subsequently, coexpression of SlNPPS and MsLS in the downstream module led to a great improvement of limonene production to 694.61 mg/L. Finally, metabolically engineered strain ELIM78 produced 1.29 g/L of limonene in 84 h by fed-batch fermentation in a shake-flask. This is the first report on limonene biosynthesis in E. coli using neryl pyrophosphate synthase, which has promising potential for producing other monoterpenes.

Low dark current organic photodetectors (OPDs) with a conventional structure consisting of poly(3-hexylthiophene) and [6,6]-phenyl-C 61 -butyric acid methyl ester (PCBM) as active layer have been fabricated by spray-coating. Tuning the thickness of active layer and thermal annealing process for the spray-coated OPDs results in a remarkable performance with a low dark current density ( J d ) of 2.90 × 10 -8 A/cm 2 at reverse bias of 1 V. The impact of thermal annealing on the performance of sprayed OPDs is also investigated by the impedance analysis for mechanistic understanding. Our results demonstrate that the optimization of PCBM cluster and interfacial contact between the active layer and the metal electrode tailored by thermal annealing, respectively, could effectively reduce the J d and increase the sensitivity of sprayed OPDs. The control of PCBM cluster is more important than the interfacial contact between the layers for improving J d . In addition, structural characterization of the active layer studied by synchrotron small-angle X-ray scattering technique reveals why the spray-coated process can achieve the lowest dark current due to the favorable structure.

A universal strategy was reported that enables functional group-capped nanostructures with various morphologies and compositions to be coated by porphyrin metal-organic framework (MOF). Based on the nanostructure-induced heterogeneous nucleation, the controlled growth of MOF shell on the surface of nanostructures can be realized. It was demonstrated that this modification strategy can realize controlled growth of porphyrin MOF on a series of organic and inorganic nanostructures, such as polydopamine (PDA) nanoparticles, PDA@Pt nanoparticles, graphene oxide sheets, and Au nanorods. The as-prepared composites exhibit excellent catalytic and optical properties that originate from the nanostructure as well as the coated porphyrin MOF. We further explored the potential applications of PDA@MOF and PDA@Pt@MOF in nanomedicine and photocatalysis.

To overcome cancer-associated immunosuppression, we prepared a dual-targeting vector to deliver CpG oligodeoxynucleotides (ODN) to macrophages. The dual-targeting system composed of mannosylated carboxymethyl chitosan (MCMC)/hyaluronan (HA) for macrophage targeting and protamine sulfate for ODN complexation was prepared by self-assembly. The effects of ODN delivery on immune cells was studied in J774A.1 cells. Due to the enhanced delivery efficiency, the dual-targeting delivery system exhibits a higher immune stimulatory activity compared with the monotargeting delivery system containing either MCMC or HA, resulting in a dramatically enhanced secretion of proinflammatory cytokines and a successful shift to activated macrophages (M1). Besides macrophages, the influence of the delivery system on tumor cells (MCF-7) was also investigated. In MCF-7 cells, the increased expressions of nuclear transcription factor-κB (NF-κB), PIK3R3, and phosphorylated protein kinase B (p-Akt) caused by activated NF-κB and phosphoinositide 3-kinase/Akt signalings were observed. Nevertheless, upregulated Fas as well as Fas ligand (FasL) may induce Fas/FasL-mediated apoptosis, which results in the increased expressions of caspases in tumor cells.

The impact of the morphological stability of the donor/acceptor mixture under thermal stress on the photovoltaic properties of bulk heterojunction (BHJ) solar cells based on the poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5-b']-dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno[3,4-b]-thiophene)-2-carboxylate-2,6-diyl]/phenyl-C 61 -butyric acid methyl ester (PTB7-Th/PC 61 BM) blend is extensively investigated. Both optical microscopy and transmission electron microscopy micrographs show that long-term high-temperature aging stimulates the formation of microscale clusters, the size of which, however, is about 1 order of magnitude smaller than those observed in thermally annealed poly(3-hexylthiophene)/PC 61 BM composite film. The multilength-scale evolution of the morphology of PTB7-Th/PC 61 BM film from the scattering profiles of grazing incidence small-angle and wide-angle X-ray scattering indicates the PC 61 BM molecules spatially confine the self-organization of polymer chains into large domains during cast drying and upon thermal activation. Moreover, some PC 61 BM molecules accumulate into ∼30-40 nm clusters, the number of which increases with heating time. Therefore, the hole mobility in the active layer decays much more rapidly than the electron mobility, leading to unbalanced charge transport and degraded cell performance. Importantly, the three-component blend that is formed by replacing a small amount of PC 61 BM in the active layer with the bis-adduct of PC 61 BM (bis-PC 61 BM) exhibits robust morphology against thermal stress. Accordingly, the PTB7-Th/PC 61 BM:bis-PC 61 BM (8 wt %) device has an extremely stable power conversion efficiency.

A multifunctional nanosystem based on two-dimensional molybdenum disulfide (MoS 2 ) was developed for synergistic tumor therapy. MoS 2 was stabilized with lipoic acid (LA)-modified poly(ethylene glycol) and modified with a pH-responsive charge-convertible peptide (LA-K 11 (DMA)). Then, a positively charged photosensitizer, toluidine blue O (TBO), was loaded on MoS 2 via physical absorption. The negatively charged LA-K 11 (DMA) peptide was converted into a positively charged one under acidic conditions. Charge conversion of the peptide could reduce the binding force between positively charged TBO and MoS 2 , leading to TBO release. Furthermore, the positively charged nanosystem was easily endocytosed by cells. Photo-induced hyperthermia of MoS 2 in the tumor areas could promote TBO release and exhibited photothermal therapy. In vitro and in vivo results demonstrated that fluorescence and photo-induced reactive oxygen species (ROS) generation of TBO were severely decreased by MoS 2 under normal conditions. While in the acidic condition, the pH-responsive nanosystem exhibited a highly specific and efficient antitumor effect with TBO release and photo-induced ROS generation, suggesting to be a promising accessory for synergistic tumor therapy.

Indoor utilization of emerging photovoltaics is promising; however, efficiency characterization under room lighting is challenging. We report the first round-robin interlaboratory study of performance measurement for dye-sensitized photovoltaics (cells and mini-modules) and one silicon solar cell under a fluorescent dim light. Among 15 research groups, the relative deviation in power conversion efficiency (PCE) of the samples reaches an unprecedented 152%. On the basis of the comprehensive results, the gap between photometry and radiometry measurements and the response of devices to the dim illumination are identified as critical obstacles to the correct PCE. Therefore, we use an illuminometer as a prime standard with a spectroradiometer to quantify the intensity of indoor lighting and adopt the reverse-biased current-voltage (I-V) characteristics as an indicator to qualify the I-V sampling time for dye-sensitized photovoltaics. The recommendations can brighten the prospects of emerging photovoltaics for indoor applications.

In this study, we developed a general method to decorate plasmonic gold nanorods (GNRs) with a CD44-targeting functional polymer, containing a hyaluronic acid (HA)-targeting moiety and a small molecule Glut1 inhibitor of diclofenac (DC), to obtain GNR/HA-DC. This nanosystem exhibited the superiority of selectively sensitizing tumor cells for photothermal therapy (PTT) by inhibiting anaerobic glycolysis. Upon specifically targeting CD44, sequentially time-dependent DC release could be achieved by the trigger of hyaluronidase (HAase), which abundantly existed in tumor tissues. The released DC depleted the Glut1 level in tumor cells and induced a cascade effect on cellular metabolism by inhibiting glucose uptake, blocking glycolysis, decreasing ATP levels, hampering heat shock protein (HSP) expression, and ultimately leaving malignant cells out from the protection of HSPs to stress (e.g., heat), and then tumor cells were more easy to kill. Owing to the sensitization effect of GNR/HA-DC, CD44 overexpressed tumor cells could be significantly damaged by PTT with an enhanced therapeutic efficiency in vitro and in vivo.

Electrospray ionization mass spectrometry (ESI-MS) is powerful for determining enzymatic reaction kinetics because of its soft ionization nature. However, it is limited to use ESI-favored solvents containing volatile buffers (e.g., ammonium acetate). In addition, lack of a quenching step for online ESI-MS reaction monitoring might introduce inaccuracy, due to the possible acceleration of reaction in the sprayed microdroplets. To overcome these issues, this study presents a new approach for online measuring enzymatic reaction kinetics using desorption electrospray ionization mass spectrometry (DESI-MS). By using DESI-MS, enzymatic reaction products in a buffered aqueous media (e.g., a solution containing Tris buffer or high concentration of inorganic salts) could be directly detected. Furthermore, by adjusting the pH and solvent composition of the DESI spray, reaction can be online quenched to avoid the postionization reaction event, leading to fast and accurate measurement of kinetic constants. Reaction time control can be obtained simply by adjusting the injection flow rates of enzyme and substrate solutions. Enzymatic reactions examined in this study include hydrolysis of 2-nitrophenyl-β-D-galactopyranoside by β-galactosidase and hydrolysis of acetylcholine by acetylcholinesterase. Derived Michaelis-Menten constants K m for these two reactions were determined to be 214 μM and 172 μM, respectively, which are in good agreement with the values of 300 μM and 230 μM reported in literature, validating the DESI-MS approach. Furthermore, this time-resolved DESI-MS also allowed us to determine K m and turnover number k cat for trypsin digestion of angiotensin II (K m and k cat are determined to be 6.4 mM and 1.3 s -1 , respectively).

Discovering advanced materials for regulating cell death is of great importance in the development of anticancer therapy. Herein, by harnessing the recently discovered oxidative stress regulation ability of p53 and the Fenton reaction inducing capability of metal-organic network (MON), MON encapsulated with p53 plasmid (MON-p53) was designed to eradicate cancer cells via ferroptosis/apoptosis hybrid pathway. After confirming the detailed mechanism of MON-p53 in evoking ferroptosis, we further discovered that MON-p53 mediated a "bystander effect" to further sensitize cancer cells toward the MON-p53 induced ferroptosis. A 75-day anticancer experiment indicated that MON-p53 treatment not only suppressed the tumor growth but also prolonged the life-span of tumor bearing mice. Owing to its ability to promote intracellular oxidative stress, MON-p53 decreased the blood metastasis, lung metastasis, and liver metastasis. As a consequence, discovering methods to induce cell ferroptosis would provide a new insight in designing anticancer materials.