Two High-Quality Cygnus Genome Assemblies Reveal Genomic Variations Associated with Plumage Color.

As an exemplary model for examining molecular mechanisms responsible for extreme phenotypic variations, plumage color has garnered significant interest. The Cygnus genus features two species, Cygnus olor and Cygnus atratus, that exhibit striking disparities in plumage color. However, the molecular foundation for this differentiation has remained elusive. Herein, we present two high-quality genomes for C. olor and C. atratus, procured using the Illumina and Nanopore technologies. The assembled genome of C. olor was 1.12 Gb in size with a contig N50 of 26.82 Mb, while its counterpart was 1.13 Gb in size with a contig N50 of 21.91 Mb. A comparative analysis unveiled three genes (TYR, SLC45A2, and SLC7A11) with structural variants in the melanogenic pathway. Notably, we also identified a novel gene, PWWP domain containing 2A (PWWP2A), that is related to plumage color, for the first time. Using targeted gene modification analysis, we demonstrated the potential genetic effect of the PWWP2A variant on pigment gene expression and melanin production. Finally, our findings offer insight into the intricate pattern of pigmentation and the role of polygenes in birds. Furthermore, these two high-quality genome references provide a comprehensive resource and perspective for comparative functional and genetic studies of evolution within the Cygnus genus.

Resequencing of Rosa rugosa accessions revealed the history of population dynamics, breed origin, and domestication pathways.

BACKGROUND: Rosa rugosa is a shrub that originated in China and has economic and ecological value. However, during the development of R. rugosa, the genetic background was chaotic, and the genetic structure among different wild populations was unclear, as well as wild and cultivated accessions. Here, we report whole-genome resequencing of wild and cultivated R. rugosa accessions. RESULTS: A total of 19,041,284 SNPs were identified in 188 R. rugosa accessions and 3 R. chinensis accessions by resequencing. Population genetic analysis revealed that cultivated and wild groups were separated very early. All R. rugosa accessions were divided into 8 categories based on genetic structure: (1) Weihai, Yantai, and Liaoning category, (2) Jilin category, and (3) Hammonasset category (above three are wild); (4) traditional varieties, (5) hybrids between R. rugosa and R. chinensis, (6) Zizhi Rose, (7) Kushui Rose, (8) hybrids between R. rugosa and R. multiflora. We found that the heterozygosity and genetic diversity of wild accessions were generally lower than those of cultivated individuals. The genes that were selected during cultivation were identified, and it was found that these genes were mainly related to environmental adaptation and growth. CONCLUSIONS: The Jilin population was the oldest population and later migrated to Liaoning and then migrated to Yantai and Weihai by sea regression in the Bohai Basin. The Hammonasset naturalized population probably originated from the Jilin population and then experienced separate differentiation. The long-term asexual reproduction pattern of R. rugosa decreased genetic diversity in the wild population. During R. rugosa cultivation, the ancestors of the Jilin population were involved in breeding traditional varieties, after which almost no wild individuals were engaged in breeding. However, in recent decades, cross breeding of R. rugosa started the utilization of wild germplasms. In comparison, some other species play important roles in variety formation. Few genes related to economic traits were selected, suggesting no directional domestication in the R. rugosa cultivation process.

HX009, a novel BsAb dual targeting PD1 x CD47, demonstrates potent anti-lymphoma activity in preclinical models.

Both PD1/PD-L1 and CD47 blockades have demonstrated limited activity in most subtypes of NHL save NK/T-cell lymphoma. The hemotoxicity with anti-CD47 agents in the clinic has been speculated to account for their limitations. Herein we describe a first-in-class and rationally designed bispecific antibody (BsAb), HX009, targeting PD1 and CD47 but with weakened CD47 binding, which selectively hones the BsAb for tumor microenvironment through PD1 interaction, potentially reducing toxicity. In vitro characterization confirmed: (1) Both receptor binding/ligand blockade, with lowered CD47 affinity; (2) functional PD1/CD47 blockades by reporter assays; (3) T-cell activation in Staphylococcal-enterotoxin-B-pretreated PBMC and mixed-lymphocyte-reaction. In vivo modeling demonstrated antitumor activity in Raji-B and Karpass-229-T xenograft lymphomas. In the humanized mouse syngeneic A20 B-lymphoma (huCD47-A20) HuGEMM model, which has quadruple knocked-in hPD1xhPD-L1xhCD47xhSIRPα genes and an intact autologous immune-system, a contribution of effect is demonstrated for each targeted biologic (HX008 targeting PD1 and SIRPα-Fc targeting CD47), which is clearly augmented by the dual targeting with HX009. Lastly, the expression of the immune-checkpoints PD-L1/L2 and CD47 seemed co-regulated among a panel of lymphoma-derived-xenografts, where HX009 maybe more effective in those with upregulated CD47. Our data warrants HX009's further clinical development for treating NHLs.

Population genomic analysis provides evidence of the past success and future potential of South China tiger captive conservation.

BACKGROUND: Among six extant tiger subspecies, the South China tiger (Panthera tigris amoyensis) once was widely distributed but is now the rarest one and extinct in the wild. All living South China tigers are descendants of only two male and four female wild-caught tigers and they survive solely in zoos after 60 years of effective conservation efforts. Inbreeding depression and hybridization with other tiger subspecies were believed to have occurred within the small, captive South China tiger population. It is therefore urgently needed to examine the genomic landscape of existing genetic variation among the South China tigers. RESULTS: In this study, we assembled a high-quality chromosome-level genome using long-read sequences and re-sequenced 29 high-depth genomes of the South China tigers. By combining and comparing our data with the other 40 genomes of six tiger subspecies, we identified two significantly differentiated genomic lineages among the South China tigers, which harbored some rare genetic variants introgressed from other tiger subspecies and thus maintained a moderate genetic diversity. We noticed that the South China tiger had higher FROH values for longer runs of homozygosity (ROH > 1 Mb), an indication of recent inbreeding/founder events. We also observed that the South China tiger had the least frequent homozygous genotypes of both high- and moderate-impact deleterious mutations, and lower mutation loads than both Amur and Sumatran tigers. Altogether, our analyses indicated an effective genetic purging of deleterious mutations in homozygous states from the South China tiger, following its population contraction with a controlled increase in inbreeding based on its pedigree records. CONCLUSIONS: The identification of two unique founder/genomic lineages coupled with active genetic purging of deleterious mutations in homozygous states and the genomic resources generated in our study pave the way for a genomics-informed conservation, following the real-time monitoring and rational exchange of reproductive South China tigers among zoos.

A living biobank of matched pairs of patient-derived xenografts and organoids for cancer pharmacology.

Patient-derived tumor xenograft (PDX)/organoid (PDO), driven by cancer stem cells (CSC), are considered the most predictive models for translational oncology. Large PDX collections reflective of patient populations have been created and used extensively to test various investigational therapies, including population-trials as surrogate subjects in vivo. PDOs are recognized as in vitro surrogates for patients amenable for high-throughput screening (HTS). We have built a biobank of carcinoma PDX-derived organoids (PDXOs) by converting an existing PDX library and confirmed high degree of similarities between PDXOs and parental PDXs in genomics, histopathology and pharmacology, suggesting "biological equivalence or interchangeability" between the two. Here we demonstrate the applications of PDXO biobank for HTS "matrix" screening for both lead compounds and indications, immune cell co-cultures for immune-therapies and engineering enables in vitro/in vivo imaging. This large biobank of >550 matched pairs of PDXs/PDXOs across different cancers could become powerful tools for the future cancer drug discovery.

Predictors of Long-Time Survivors in Nonmetastatic Colorectal Signet Ring Cell Carcinoma: A Large Population-Based Study.

Background: Colorectal signet ring cell carcinoma (SRCC) is a rare and distinct subtype of colorectal cancer (CRC), with extremely poor prognosis and aggressive tumor biological behavior. In this study, we aimed to analyze the clinicopathological characteristics and to identify the independent predictors of long-time survivors (LTSs) of nonmetastatic colorectal SRCC. Methods: Patients diagnosed with nonmetastatic colorectal SRCC were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. We compared and analyzed the clinicopathological characteristics between LTSs (patients survived over 5 years) and non-LTSs (patients survived of or less than 5 years). Afterwards, multivariate logistic regression analysis was used to identify independent predictors of LTSs, which were further used to construct a nomogram model to predict the probability of being LTSs. Results: We enrolled 2050 patients with nonmetastatic colorectal SRCC, consisting of 1441 non-LTSs and 609 LTSs. Multivariate logistic regression analysis revealed that race, marital status, tumor infiltration, lymph node involvement, and primary tumor treatment were independent predictors of LTSs. In addition, these five parameters were incorporated into a nomogram model to predict the probability of being LTSs. In terms of the model performance, the calibration curve revealed good agreement between observed and predicted probability of LTSs, and receiving operator characteristic curve showed acceptable discriminative capacity in the training and validation cohorts. Conclusion: Collectively, we analyzed and profiled the clinicopathological characteristics of LTSs in patients with nonmetastatic colorectal SRCC. Race, marital status, T stage, N stage, and primary tumor treatment were independent predictors of LTSs.

Identification of DNAH17 Variants in Han-Chinese Patients With Left-Right Asymmetry Disorders.

The formation of left-right asymmetry of the visceral organs is a conserved feature of the human body, and the asymmetry specification of structure and function is precisely orchestrated by multiple regulatory mechanisms. The abnormal results of organ positioning situs arise from defective cilia structure or function during embryogenesis in humans. In this study, we recruited two unrelated Han-Chinese families with left-right asymmetry disorders. The combination of whole-exome sequencing and Sanger sequencing identified two compound heterozygous variants: c.4109C>T and c.9776C>T, and c.612C>G and c.8764C>T in the dynein axonemal heavy chain 17 gene (DNAH17) in two probands with left-right asymmetry disorders. We report for the first time a possible association between DNAH17 gene variants and left-right asymmetry disorders, which is known as a causal gene for asthenozoospermia. Altogether, the findings of our study may enlarge the DNAH17 gene variant spectrum in human left-right asymmetry disorders, pave a way to illustrate the potential pathogenesis of ciliary/flagellar disorders, and provide supplementary explanation for genetic counseling.

Core-shell Cu@C@ZIF-8 composite: a high-performance electrode material for electrochemical sensing of nitrite with high selectivity and sensitivity.

Herein, an efficient electrochemical sensing platform is proposed for selective and sensitive detection of nitrite on the basis of Cu@C@Zeolitic imidazolate framework-8 (Cu@C@ZIF-8) heterostructure. core-shell Cu@C@ZIF-8 composite was synthesized by pyrolysis of Cu-metal-organic framework@ZIF-8 (Cu-MOF@ZIF-8) in Ar atmosphere on account of the difference of thermal stability between Cu-MOF and ZIF-8. For the sensing system of Cu@C@ZIF-8, ZIF-8 with proper pore size allows nitrite diffuse through the shell, while big molecules cannot, which ensures high selectivity of the sensor. On the other hand, Cu@C as electrocatalyst promotes the oxidation of nitrite, thereby resulting high sensitivity of the sensor. Accordingly, the Cu@C@ZIF-8 based sensor presents excellent performance for nitrite detection, which achieves a wide linear response range of 0.1-300.0µM, and a low limit of detection of 0.033µM. In addition, the Cu@C@ZIF-8 sensor possesses excellent stability and reproducibility, and was employed to quantify nitrite in sausage samples with recoveries of 95.45%-104.80%.

A high-quality chromosome-level genome of wild Rosa rugosa.

Rosa rugosa is an important shrub with economic, ecological, and pharmaceutical value. A high-quality chromosome-scale genome for R. rugosa sequences was assembled using PacBio and Hi-C technologies. The final assembly genome sequences size was about 407.1 Mb, the contig N50 size was 2.85 Mb, and the scaffold N50 size was 56.6 Mb. More than 98% of the assembled genome sequences were anchored to seven pseudochromosomes (402.9 Mb). The genome contained 37,512 protein-coding genes, with 37,016 genes (98.68%) that were functionally annotated, and 206.67 Mb (50.76%) of the assembled sequences are repetitive sequences. Phylogenetic analyses indicated that R. rugosa diverged from Rosa chinensis ∼6.6 million years ago, and no lineage-specific whole-genome duplication event occurred after divergence from R. chinensis. Chromosome synteny analysis demonstrated highly conserved synteny between R. rugosa and R. chinensis, between R. rugosa and Prunus persica as well. Comparative genome and transcriptome analysis revealed genes related to colour, scent, and environment adaptation. The chromosome-level reference genome provides important genomic resources for molecular-assisted breeding and horticultural comparative genomics research.

Effects of lncRNA ANRIL-knockdown on the proliferation, apoptosis and cell cycle of gastric cancer cells.

Gastric cancer is one of the most common types of malignant tumor of the gastrointestinal tract worldwide. Cisplatin (DDP) is a commonly used chemotherapeutic drug in the clinic; however, the resistance of gastric cancer cells to DDP limits its efficacy. In the present study, drug-resistant gastric cancer cell lines were constructed using the stepwise continuous selection method, and the relative expression levels of long non-coding RNA (lncRNA) CDKN2B antisense RNA 1 (ANRIL) and microRNA (miR)-181a-5p were detected using reverse transcription-quantitative PCR. The knockdown of lncRNA ANRIL and miR-181a-5p expression was performed by transfection with shRNA-ANRIL and an miR-181a-5p inhibitor, respectively. Cellular proliferation and sensitivity to DDP were assessed using Cell Counting Kit-8 analysis. Cell apoptosis and cell cycle distribution were assessed using flow cytometry and western blotting. The binding relationships between ANRIL, miR-181a-5p and cyclin G1 (CCNG1) were verified using a dual luciferase reporter assay. The results revealed that the expression levels of miR-181a-5p were downregulated in all drug-resistant cell lines. ANRIL-knockdown inhibited cellular proliferation, and promoted apoptosis and cell cycle arrest; however, following the knockdown of miR-181a-5p, the inhibition of cell cycle arrest was alleviated. Notably, miR-181a-5p, ANRIL and CCNG1 were found to have targeting relationships. In conclusion, the findings of the present study suggested that knocking down the expression of ANRIL inhibited cellular proliferation, and promoted apoptosis and cell cycle arrest. Furthermore, its downstream target, miR-181a-5p, inhibited the proliferation of drug-resistant cells and enhanced their sensitivity to DDP.

Genomes reveal selective sweeps in kiang and donkey for high-altitude adaptation.

Over the last several hundred years, donkeys have adapted to high-altitude conditions on the Tibetan Plateau. Interestingly, the kiang, a closely related equid species, also inhabits this region. Previous reports have demonstrated the importance of specific genes and adaptive introgression in divergent lineages for adaptation to hypoxic conditions on the Tibetan Plateau. Here, we assessed whether donkeys and kiangs adapted to the Tibetan Plateau via the same or different biological pathways and whether adaptive introgression has occurred. We assembled a de novo genome from a kiang individual and analyzed the genomes of five kiangs and 93 donkeys (including 24 from the Tibetan Plateau). Our analyses suggested the existence of a strong hard selective sweep at the EPAS1 locus in kiangs. In Tibetan donkeys, however, another gene, i.e., EGLN1, was likely involved in their adaptation to high altitude. In addition, admixture analysis found no evidence for interspecific gene flow between kiangs and Tibetan donkeys. Our findings indicate that despite the short evolutionary time scale since the arrival of donkeys on the Tibetan Plateau, as well as the existence of a closely related species already adapted to hypoxia, Tibetan donkeys did not acquire adaptation via admixture but instead evolved adaptations via a different biological pathway.

Genome sequences reveal global dispersal routes and suggest convergent genetic adaptations in seahorse evolution.

Seahorses have a circum-global distribution in tropical to temperate coastal waters. Yet, seahorses show many adaptations for a sedentary, cryptic lifestyle: they require specific habitats, such as seagrass, kelp or coral reefs, lack pelvic and caudal fins, and give birth to directly developed offspring without pronounced pelagic larval stage, rendering long-range dispersal by conventional means inefficient. Here we investigate seahorses' worldwide dispersal and biogeographic patterns based on a de novo genome assembly of Hippocampus erectus as well as 358 re-sequenced genomes from 21 species. Seahorses evolved in the late Oligocene and subsequent circum-global colonization routes are identified and linked to changing dynamics in ocean currents and paleo-temporal seaway openings. Furthermore, the genetic basis of the recurring "bony spines" adaptive phenotype is linked to independent substitutions in a key developmental gene. Analyses thus suggest that rafting via ocean currents compensates for poor dispersal and rapid adaptation facilitates colonizing new habitats.

A systematic review and meta-analysis on the efficacy of Compound Kushen Injection in 3 kinds of digestive tract tumor.

BACKGROUND: Chemotherapy has become the main means to prolong the life of patients with advanced digestive tract cancer; however, it is associated with serious toxicity and side effects. Compound Kushen Injection (CKI) is a pure Chinese herbal preparation, which can assist chemotherapy, inhibit tumor cell proliferation, and reduce adverse reactions of chemotherapy. In this study, we systematically evaluated reports of CKI as an adjuvant to chemotherapeutic treatment of digestive tract cancer in recent years and provided evidence for clinical diagnosis and treatment. METHODS: The databases of PubMed, Chinese Biomedical Literature (CBM), China National Knowledge Infrastructure (CNKI) and Web Of Science were searched for clinical randomized controlled trials (RCTs) related to adjuvant chemotherapy with CKI in the treatment of advanced gastrointestinal tumors published from January 2000 to September 2021. After screening the qualified literatures, RevMan 5.4 software was used to evaluate the bias of the included literatures and perform meta-analysis. RESULTS: A total of 12 articles were included in the selection, incorporating 1080 study participants in all; meta-analysis results showed that application of the CKI in the process of chemotherapy for digestive tract tumors could improve the efficacy [odds ratio (OR) =3.11; 95% confidence interval (CI): 2.26 to 4.47, Z=7.00, P<0.00001], increase the patients' median survival time (months) (OR =3.00; 95% CI: 1.47 to 4.52, Z=3.84, P=0.0001), increase the level of CD3+ [mean difference (MD) =4.11; 95% CI: 3.24 to 4.98], CD4+ level (MD =8.24; 95% CI: 3.72 to 12.76), reduce the CD8+ level (MD =-5.42; 95% CI: -8.09 to -2.76), reduce the tumor markers carcinoembryonic antigen (CEA; MD =-14.26; 95% CI: -14.81 to -13.71), CA199 (MD =-138.87; 95% CI: -143.21 to -132.52), and reduce the adverse reactions of chemotherapy: leukopenia (OR =0.28; 95% CI: 0.19 to 0.43), thrombocytopenia (OR =0.38; 95% CI: 0.24 to 061), decreased hemoglobin (OR =0.55; 95% CI: 0.31 to 0.98), and nausea and vomiting symptoms (OR =0.35; 95% CI: 0.24 to 0.53). DISCUSSION: Adjuvant chemotherapy with CKI in the treatment of digestive tract tumors can effectively improve the symptoms of patients, improve immunity, reduce the level of serum tumor markers, improve efficacy, and reduce toxic and side effects.

Prussian blue-carboxylated MWCNTs/ZIF-67 composite: a new electrochemical sensing platform for paracetamol detection with high sensitivity.

In this study, the composite of Prussian blue-carboxylated MWCNTs/ZIF-67 (PB-MWCNTs-COOH/ZIF-67) was synthesized and used as modified electrode material to fabricate an electrochemical sensor for the determination of paracetamol (PAR). In this sensor system, negatively charged MWCNTs-COOH as support for the immobilization of positively charged PB can effectively avoid the agglomeration of PB and enhance the stability, conductivity and catalytic activity of the composite. ZIF-67 particles coating outside PB-MWCNTs-COOH promotes the concentration of PAR. Benefiting from the synergistic effect, the PB-MWCNTs-COOH/ZIF-67 based sensor exhibits significantly improved electrochemical sensing behavior toward the oxidation of PAR. Under the optimum conditions, the PAR sensor presents wide linear ranges of 0.01-70 µM with a low limit of detection of 3.3 nM (S/N = 3). The method also possesses long-term stability, good reproducibility and selectivity, and was employed to the determination of PAR contents in PAR tablets sample.

Sensitive electrochemical platform for trace determination of Pb2+ based on multilayer Bi-MOFs/reduced graphene oxide films modified electrode.

A multilayer Bi-BTC/reduced graphene oxide (Bi-BTC/rGO) (BTC, 1,3,5-benzenetricarboxylic acid) film electrode was adopted to construct a highly sensitive Pb2+ electrochemical sensor. The multilayer Bi-BTC/rGO films were prepared via alternate cast of Bi-BTC and graphene oxide (GO) on a glassy carbon electrode, followed by electro-reduction of the GO components. Bi-BTC has porous broom-like structure and its organic ligand has abundant functional groups, which are favorable for Pb2+ adsorption and preconcentration. The introduction of rGO layer improves the conductivity of the MOFs material. Moreover, the multilayer composite structure greatly increased the exposure of active sites and the surface area of reactive contact, finally realizing the highly sensitive detection of Pb2+. Pb2+ was determined by differential pulse anodic stripping voltammetry and the response current was recorded at - 0.62 V. The [Bi-BTC/rGO]2 electrode provides a wide linear response ranging from 0.062 to 20.72 µg/L and a low limit of detection (LOD) of 0.021 µg/L (S/N = 3) for Pb2+, which is lower than the guideline value proposed by the World Health Organization. The method has been applied to determine Pb2+ in industrial wastewater with recoveries of 99.2-104% and RSDs of 3.4-4.0% (n = 3). Graphical abstract Graphical abstract Schematic representation of an electrochemical sensor for the detection of Pb2+ was designed based on long broom-like structure bismuth(II) metallic organic framework/reduced graphene oxide ([Bi-BTC /rGO]2).

Effect of the Al2O3 Deposition Method on Parylene C: Highlights on a Nanopillar-Shaped Surface.

Parylene C (PC) has attracted tremendous attention throughout the past few years due to its extraordinary properties such as high mechanical strength and biocompatibility. When used as a flexible substrate and combined with high-κ dielectrics such as aluminum oxide (Al2O3), the Al2O3/PC stack becomes very compelling for various applications in fields such as biomedical microsystems and microelectronics. For the latter, the atomic layer deposition of oxides is particularly needed as it allows the deposition of high-quality and nanometer-scale oxide thicknesses. In this work, atomic layer deposition (ALD) and electron beam physical vapor deposition (EBPVD) of Al2O3 on a 15 µm-thick PC layer are realized and their effects on the Al2O3/PC resulting stack are investigated via X-ray photoelectron spectroscopy combined with atomic force microscopy. An ALD-based Al2O3/PC stack is found to result in a nanopillar-shaped surface, while an EBPVD-based Al2O3/PC stack yields an expected smooth surface. In both cases, the Al2O3/PC stack can be easily peeled off from the reusable SiO2 substrate, resulting in a flexible Al2O3/PC film. These fabrication processes are economic, high yielding, and suitable for mass production. Although ALD is particularly appreciated in the semiconducting industry, EBPVD is here found to be better for the realization of the Al2O3/PC flexible substrate for micro- and nanoelectronics.

NiO@Ni-MOF nanoarrays modified Ti mesh as ultrasensitive electrochemical sensing platform for luteolin detection.

A novel electrochemical sensor was constructed based on three-dimensional NiO@Ni-MOF nanoarrays modified Ti mesh (NiO@Ni-MOF/TM). NiO nanoarrays were firstly produced on conductive TM using hydrothermal and carbonization method, and then Ni-MOFs were directly grown on the surface of NiO nanoarrays through self-template strategy. The morphology and structure of the prepared materials were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The as-prepared NiO@Ni-MOF/TM was used as electrochemical sensor for investigating electrochemical behaviors of luteolin flavonoid. The composite electrode combined the excellent enrichment ability of Ni-MOF, high catalysis of NiO nanoarrays with the superior electronic conductivity of TM substrate, enabling ultra-sensitive detection towards luteolin with a low limit of detection (LOD) of 3 pM (S/N = 3). Besides, with favorable stability and selectivity, the fabricated sensor was applied in the determination of luteolin in actual samples with satisfactory results.

Self-template synthesis of flower-like hierarchical graphene/copper oxide@copper(II) metal-organic framework composite for the voltammetric determination of caffeic acid.

Flower-like graphene/CuO@Cu-BTC (GR/CuO@Cu-BTC) composite was employed as electrode material for the voltammetric determination of caffeic acid (CA) in the wine. The composite material was prepared via the self-template method. In this synthetic process, budlike CuO not only acts as the template, but also provides Cu2+ ions for in situ growth of the Cu-BTC shell. The utilization of GR as petal greatly boosts the stability and electronic conductivity of CuO@Cu-BTC. The GR/CuO@Cu-BTC composite possesses unique structural features with high specific surface area and good conductivity, exhibiting excellent electrocatalytic activity towards the oxidation of CA. Under optimized conditions, the sensor shows a good linear response to CA concentration over the range 0.020-10.0 µM, together with a low limit of detection (LOD) of 7.0 nM. Selectivity, reproducibility, and stability were investigated, and the method has been applied for the determination of CA in wine samples. Graphical abstract Schematic representation of electrochemical sensor for the detection of caffeic acid was designed based on flower-like graphene/copper oxide@copper(II) metal-organic framework (GR/CuO@Cu-BTC) composite electrode material.

Mxene/carbon nanohorn/ß-cyclodextrin-Metal-organic frameworks as high-performance electrochemical sensing platform for sensitive detection of carbendazim pesticide.

Pesticides play an important role in agricultural fields, but the pesticide residues pose strong hazardous to human health, thus designing sensitive and fast method for pesticides monitor is highly urgent. Herein, nanoarchitecture of Mxene/carbon nanohorns/ß-cyclodextrin-Metal-organic frameworks (MXene/CNHs/ß-CD-MOFs) was exploited as electrochemical sensing platform for carbendazim (CBZ) pesticide determination. ß-CD-MOFs combined the properties of host-guest recognition of ß-CD and porous structure, high porosity and pore volume of MOFs, enabling high adsorption capacity for CBZ. MXene/CNHs possessed large specific surface area, plenty of available active sites, high conductivity, which afforded more mass transport channels and enhances the mass transfer capacity and catalysis for CBZ. With the synergistic effect of MXene/CNHs and ß-CD-MOFs, the MXene/CNHs/ß-CD-MOFs electrode extended a wide linear range from 3.0 nM to 10.0 µM and a low limit of detection (LOD) of 1.0 nM (S/N = 3). Additionally, the prepared sensor also demonstrated high selectivity, reproducibility and long-term stability, and satisfactory applicability in tomato samples.

A CuO-CeO2 composite prepared by calcination of a bimetallic metal-organic framework for use in an enzyme-free electrochemical inhibition assay for malathion.

An enzyme-free electrochemical method is described for the determination of trace levels of malathion. It is based on a nanostructured copper-cerium oxide (CuO-CeO2) composite prepared by calcination of a Cu(II)/Ce(III) metal-organic framework. The morphology, crystal structure and elemental composition of composite was studied by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The principle for malathion determination is based on the fact that the redox signal of CuO (best measured at around -0.1 V vs. SCE) (at 100 mV/s) is inhibited by malathion due to affinity between CuO and the sulfur groups of malathion. The introduction of CeO2 into the composite system further improves the analytical performance. This is attributed to the unique microstructure and the synergistic effect between CuO and CeO2. Experimental parameters like solution pH value, Cu/Ce molar ratio, accumulation potential, accumulation time, and CuO-CeO2 volume on the electrode were optimized. The assay has a linear range of 10 fM to 100 nM and a 3.3 fM detection limit (at S/N = 3). The electrode is selectively inhibited by malathion even in the presence of potentially interfering substances. Graphical abstract A sensitive and effective enzyme-free electrochemical sensor has been developed for the detection of malathion based on CuO-CeO2 composite derived from bimetallic metal-organic frameworks.