Bafi A1 inhibits nano-copper oxide-induced mitochondrial damage by reducing the release of copper from lysosomes.

This study demonstrated that both copper oxide nanoparticles (CuO-NPs) and copper nanoparticles (Cu-NPs) can cause swelling, inflammation, and cause damage to the mitochondria of alveolar type II epithelial cells in mice. Cellular examinations indicated that both CuO-NPs and Cu-NPs can reduce cell viability and harm the mitochondria of human bronchial epithelial cells, particularly Beas-2B cells. However, it is clear that CuO-NPs exhibit a more pronounced detrimental effect compared with Cu-NPs. Using bafilomycin A1 (Bafi A1), an inhibitor of lysosomal acidification, was found to enhance cell viability and alleviate mitochondrial damage caused by CuO-NPs. Additionally, Bafi A1 also reduces the accumulation of dihydrolipoamide S-acetyltransferase (DLAT), a marker for mitochondrial protein toxicity, induced by CuO-NPs. This observation suggests that the toxicity of CuO-NPs depends on the distribution of copper particles within cells, a process facilitated by the acidic environment of lysosomes. The release of copper ions is thought to be triggered by the acidic conditions within lysosomes, which aligns with the lysosomal Trojan horse mechanism. However, this association does not seem to be evident with Cu-NPs.

Homogeneous Binary Visual and Fluorescence Detection of Tetanus Toxoid in Clinical Samples Based on Enzyme-Free Parallel Hybrid Chain Reaction.

Here, we report a simple aptamer-based toxoid test with both fluorescence and binary visual readouts. This test is established based on our recent finding that CdTe quantum dots could differentiate DNA templated Cu NPs from Cu2+. Through the further integration with enzyme-free triple parallel hybridization chain reaction, cation exchange reaction, and inkjet printing, we demonstrated specific detection of tetanus toxoid with a limit-of-detection (LOD) of 0.25 fg/mL using fluorescence readout. Using color- and distance-based binary visual readouts, we were able to achieve LODs of 10 fg/mL and 1 fg/mL, respectively. The quantitative test results for tetanus toxoid using both fluorescence and visual readouts were successfully validated in 84 clinical serum samples. Moreover, our strategy also enabled accurate monitoring of tetanus toxoid levels in patients before and after drug treatment. On the basis of our clinical test results, we recommend a cutoff value of 5 fg/mL for tetanus infection.

Bioinspired Pd-Cu Alloy Nanoparticles as Accept Agent for Dye Degradation Performances.

Dye degradation is a key reaction in organic decomposition production through electron donor transferring. Palladium (Pd) is the best-known element for synthesis Pd-based catalyst, the surface status determines the scope of relative applications. Here we first prepare Pd-Cu alloy nanoparticles (NPs) by co-reduction of Cu(acac)2 (acac = acetylacetonate) and Pd(C5HF6O2)2 in the presence of sodium borohydride (NaBH4) and glutathione (GSH). The obtained Pd-Cu is about ~10 nm with super-hydrophilicity in aqueous mediums. The structural analysis clearly demonstrated the uniform distribution of Pd and Cu element. The colloidal solution keeps stability even during 30 days. Bimetallic Pd-Cu NPs shows biocompatibility in form of cell lines (IMEF, HACAT, and 239 T) exposed to colloidal solution (50 µg mL-1) for 2 days. It shows the catalytic multi-performance for dye degradation such as methyl orange (MO), rhodamine B (RhB), and methylene blue (MB), respectively. The as-synthesized nanoparticles showed one of the best multiple catalytic activities in the industrially important (electro)-catalytic reduction of 4-nitrophenol (4-NP) to corresponding amines with noticeable reduced reaction time and increased rate constant without the use of any large area support. In addition, it exhibits peroxidase-like activity in the 3, 3', 5, 5'-Tetramethylbenzidine (TMB) color test and exhibit obvious difference with previous individual metal materials. By treated with high intensity focused ultrasound filed (HIFU), Pd-Cu NPs might be recrystallized and decreased the diameters than before. The enhancement in catalytic performance is observed obviously. This work expedites rational design and synthesis of the high-hierarchy alloy catalyst for biological and environment-friendly agents.

Dynamic light scattering and zeta-potential as a tool for understanding the mechanism of pesticides binding toward individual components of transition metal nanoparticles and graphene oxide hybrids.

Pesticides present in their commercial formulations are studied for their preferable binding toward carbon-based graphene oxide (GO) or transition metal nanoparticles (Fe, Co, Ni, and Cu), present as hybrids. This simple study also reveals the mechanism of interaction of few selected different classes of pesticides, namely, λ-cyhalothrin, imidacloprid, and metsulfuron-methyl toward these hybrids. Individually, to study this comparative binding when hybrids are not used, the understanding of preferred binding toward any of these selected compounds could be challenging, costly, and time-consuming. Dynamic light scattering (DLS) is used to study the changes observed for hydrodynamic radius and zeta potential for the stability of the resulting products. This simple method can also be extended to identify the binding mechanism for other diverse set of combinations. These studies are supported by binding of GO with nanoparticles in batch adsorption and the best fit using Langmuir and Freundlich isotherms is presented. Moreover, pesticide adsorption toward GO-nanoparticle composites is also evidenced.

Copper nanoparticles against benzimidazole-resistant Monilinia fructicola field isolates.

Nano-fungicides are expected to play an important role in future plant disease management. Their unique properties include a broad antimicrobial action, increased effectiveness in lower doses, slower a.i. release and/or enhanced drug delivery and an ability to control drug-resistant pathogens, which makes them appealing candidates for use as eco-friendly antifungal alternatives to counter fungicides resistance. Copper nanoparticles (Cu-NPs) could suppress mycelial growth in both sensitive (BENS) and resistant (BEN-R) Monilinia fructicola isolates harboring the E198A benzimidazole resistance mutation, more effectively than copper oxide NPs (CuO-NPs) and Cu(OH)2. A significant synergy of Cu-NPs with thiophanate methyl (TM) was observed against BEN-S isolates both in vitro and when applied on plum fruit suggesting enhanced availability or nanoparticle induced transformation of TM to carbendazim. ATP-dependent metabolism is probably involved in the mode of fungitoxic action of Cu-NPs as indicated by the synergy observed between Cu-NPs and the oxidative phosphorylation-uncoupler fluazinam (FM). Copper ion release contributed in the toxic action of Cu-NPs against M. fructicola, as indicated by synergism experiments with ethylenediaminetetraacetic acid (EDTA), although the lack of correlation between nano and bulk/ionic copper forms indicate an additional nano-property mediated mechanism of fungitoxic action. Results suggested that Cu-NPs can be effectively used in future plant disease management as eco-friendly antifungal alternatives to counter fungicides resistance and reduce the environmental footprint of synthetic fungicides.

Role of water chemistry on stability, aggregation, and dissolution of uncoated and carbon-coated copper nanoparticles.

Intentional or accidental release of copper nanoparticles (Cu-NPs) from consumer products during manufacturing, use, and end-of-life management could pose health and ecological risks. This paper presents a detailed study on the role of water chemistry on the fate of uncoated and carbon-coated Cu-NPs dispersed in aqueous cetyltrimethylammonium bromide (CTAB) surfactant in the presence and absence of humic acids (HAs). A range of water chemistry and HAs had minimum impact on hydrodynamic diameter and zeta-potential values of uncoated and carbon-coated Cu-NPs. The water pH significantly (p < 0.001) affected the aggregation of uncoated Cu-NPs unlike that of carbon-coated Cu-NPs; however, the presence of HAs increased the stability of uncoated Cu-NPs. Although CTAB is considered as an efficient dispersant to stabilize Cu-NPs, the effect descended with time for uncoated Cu-NPs. The dissolution of Cu over time decreased with increasing pH for both uncoated (0.5-50% weight) and carbon-coated (0.5-40% weight) Cu-NPs. However, carbon-coated Cu-NPs exhibited significant dissolution (p < 0.001) at neutral pH than uncoated Cu-NPs may be due to the additional carbon it acquired during coating. Increasing HAs concentration from 0 to 15 mg L-1 at pH 5.5 inhibited aggregations but enhanced dissolution of the uncoated and carbon-coated Cu-NPs. These findings inform risk analysis of Cu-NPs including how Cu-NPs fate, mobility and bioavailability are modulated by particles coating and dispersant, HAs presence, water chemistry and exposure time in dispersion media.

Oral exposure of pregnant rats to copper nanoparticles caused nutritional imbalance and liver dysfunction in fetus.

Copper nanoparticles (Cu NPs) are increasingly used as an animal feed additive in China. In previous studies, it was determined that Cu NPs can penetrate the placental barrier, however, its toxic effects on the fetus have not yet been elucidated. Therefore, in this study, we investigated the potential fetal toxic effects of Cu NPs. Cu NPs were orally administered to pregnant Sprague-Dawley rats from gestation days (GDs) 3-18 at a dose of 60, 120, and 180 mg/kg/day. Cesarean sections were conducted on GD 19. During fetal examination, no toxicities were observed regarding general clinical signs, however, Cu NPs significantly decreased fetal body weight, body length, and liver weights. Cu ions and Cu MPs exhibited similar effects on the fetal development. Cu NPs increased the liver concentration of Cu, and decreased protein levels and Fe in fetuses. Cu NPs also increased oxidative stress and inflammation in the fetus after pregnant rats were exposed to high doses of Cu NPs. Oral exposure to Cu NPs during pregnancy increased Cu concentrations in the fetus, which not only affected fetal development, but also significantly induced oxidative stress and inflammatory responses in fetal liver. Taken together, these findings are valuable to evaluate fetal risk assessment after oral exposure of Cu NPs during pregnancy. Additional comprehensive toxicity studies are deemed necessary to clarify the underlying mechanisms involved.

Copper nanoparticle-induced uterine injury in female rats.

Copper nanoparticles (Cu-NPs) have been used increasingly in various products and applications. Although recent studies have reported that exposure to Cu-NPs leads to organ accumulation and obvious toxicity, it remains unclear whether Cu-NPs can be translocated to and cause damage in the uterus. In this study, we investigated the potential for uterine injury and gene expression patterns in female rats exposed to 3.12, 6.25, or 12.5 mg/kg/d Cu-NPs via intraperitoneal injection for 14 consecutive days. The results indicated that exposure to Cu-NPs led to significant decreases in the relative uterine weight coefficients and increases in inflammatory cell infiltration, mitochondrial swelling and vacuolization, shortened and reduced endometrial epithelial cell microvilli, and apoptosis. Furthermore, exposure to Cu-NPs increased malondialdehyde (MDA) accumulation and decreased superoxide dismutase (SOD) levels. Signal transduction mechanism studies indicated that exposure to Cu-NPs activated caspases 3, 8, and 9 and BH3 interacting domain death agonist (tBid), reduced B cell leukemia/lymphoma 2 (Bcl-2) expression, and increased the expression of apoptotic peptidase activating factor 1 (Apaf-1), BCL2-associated X, apoptosis regulator (Bax), and cytochrome c. A microarray analysis revealed significant alterations in the expression of 963 genes; of these, 622 were upregulated and 341 were downregulated. The results of further evaluations of some altered genes, including matrix metallopeptidase 12 (Mmp12), using quantitative RT-PCR agreed with the microarray findings. These results provide strong evidence that Cu-NPs can trigger both intrinsic and extrinsic apoptotic pathways to mediate uterine injury, resulting in oxidative stress-related changes in gene expression.

Synthesis and characterization of novel bactericidal Cu/HPMC BNCs using chemical reduction method for food packaging.

In this research copper nanoparticles (Cu NPs) were incorporated in the biodegradable hydroxypropyl methylcellulose (HPMC) matrix using the simple and low cost chemical reduction method for application as food packaging material. The properties of Cu/HPMC bionanocomposites (BNCs) were studied as a function of the CuSO4 concentration. Surface morphology of the film was investigated by scanning electron microscopy. Mechanical analysis and water vapor barrier properties of HPMC/Cu nanocomposites were analyzed. It was observed that mechanical and water vapor barrier properties of the films were improved by the concentration of CuSO4. The antibacterial activity of HPMC/Cu thin films were evaluated based on the diameter of inhibition zone in a disk diffusion test against Gram positive bacteria, ie, Streptococus A., S. epidermidis, S.aureus , B.cereus and Gram negative bacteria, ie, E. coli, E. faecalis, Salmonella, P. aeruginosa using Mueller Hinton agar at different concentration of CuSO4. The results revealed a greater bactericidal effectiveness for nanocomposite films containing 5 % of CuSO4. Packages prepared from HPMC/Cu nanocomposite films were used for meat packaging. The films were filled with meat and then stored at 4 °C. Microbial stability of the meat was evaluated after 3, 7, 10 and 15 days of storage. The results showed that microbial growth rate significantly reduced as a result of using this nanocomposite packaging material.

Cu-nanoparticles@ graphene nanocomposite: A robust and efficient nanocomposite for micro-solid phase extraction of trace aflatoxins in different foodstuffs.

Cu-nanoparticles-immobilized graphene (Cu@G) nanocomposite was fabricated in this study by reducing Cu(II) ions in the presence of graphene oxide using a simple chemical reduction step. Cu@G nanocomposite was applied as a sorbent for the SPE of four aflatoxins (AFs). A reusable syringe was filled with the fabricated nanocomposite and used as a sorbent for the micro-solid phase extraction of four AFs (AFB1, AFB2, AFG1, AFG2). The impact of different analytical factors was fully investigated and optimized. Excellent recoveries, ranging from 92.0 to 108.5 %, were detected when evaluating target AFs in samples of rice, maize, and pistachio. The LOD, LOQ, and linear ranges were attained under optimal circumstances in the ranges of 0.0062 µg kg-1, 0.0192 µg kg-1, and 0.0-20 µg kg-1, respectively. The discovered approach provided the dual benefits of a high enrichment capability of Cu-nanoparticles via AFs complexation and a huge porosity of graphene sheets.

Design and decoration of copper nanoparticles into lignosulfonate-starch bionanocomposite: Characterization and evaluation of its therapeutic properties on burn wound.

In this report, eco-friendly synthesis for the production of copper nanoparticles by employing the sodium lignosulfonate (NaLS) mixed starch composite (NaLS-Starch/Cu NPs). NaLS-Starch mixed hydrogel has notable reducing and stabilizing potential for preparation of Cu nanoparticles. Characterization of NaLS-Starch/Cu NPs bionanocomposite was subjected to analysis of spectroscopic and microscopic techniques, including FE-SEM, TEM, EDS-elemental mapping, particle size distribution, XRD and ICP. TEM images displayed the spherical structured NaLS-Starch/Cu NPs, averaging 5-10 nm size. NaLS-Starch/Cu NPs were applied to cure the induced burn wounds in 60 Wistar rats. A group was considered as control group. The animals were treated with basal, tetracycline 3 % and NaLS-Starch/Cu NPs 3 % for 30 days and the treatment efficacy was determined according to the burn wound area reduction and molecular and histological characteristics. Taken together, these results support therapeutic use of NaLS-Starch/Cu NPs as potent ointment that may be proposed for burn wound healing. NaLS-Starch/Cu NPs ointment increased the levels of platelet-derived growth factors (PDGF) and fibroblast growth factor (bFGF). The mean wound surface, in all groups treated by NaLS-Starch/Cu NPs was larger than control group.

Tandem hydrogenation/hydrogenolysis of furfural to 2-methylfuran over multifunctional metallic Cu nanoparticles supported ZIF-8 catalyst.

Catalytic transfer hydrogenation (CTH), that employs protic solvents as hydrogen sources to alleviate the use of molecular hydrogen H2, has gained great attention. This work, reports multifunctional, metallic Cu nanoparticles supported ZIF-8 material for CTH of furfural to a highly valued fuel additive, 2-methylfuran (2-MF) using 2-propanol. Of all as-synthesized xCu(yM)/ZIF-8 catalysts with varied NaBH4 concentration (yM) and Cu loading (x), 11Cu(1.5 M)/ZIF-8 exhibited higher catalytic activity with > 99 % FAL conversion and 93.9 % 2-MF selectivity. This is ascribed to its high specific surface area, and existence of optimum amount of Lewis acid-base sites along with Cu0 species, which are responsible for hydrogenation of furfural to furfuryl alcohol and subsequent hydrogenolysis to produce 2-MF. The present work reports a highly efficient and stable, metal-MOF hybrid material for CTH of FAL to 2-MF, which is one among the best reports available in literature, therewith suggests a promising approach for bio-oil upgradation.

Exposure to copper nanoparticles or copper sulfate dysregulated the hypothalamic-pituitary-gonadal axis, gonadal histology, and metabolites in Pelteobagrus fulvidraco.

This study evaluated the effects of chronic exposure to copper nanoparticles (Cu-NPs) and waterborne copper (CuSO4) on the reproductive system of yellow catfish (Pelteobagrus fulvidraco). Juvenile yellow catfish were exposed to 100 and 200 µg Cu/L Cu-NPs and 100 µg Cu/L CuSO4 for 42 days. The results showed clear reproductive defects in both female and male yellow catfish in the 200 µg Cu/L Cu-NPs and 100 µg Cu/L CuSO4 groups. Exposure to Cu-NPs or CuSO4 inhibited folliculogenesis and vitellogenesis in the ovaries, and spermatogenesis in the testes, accompanied by elevation of the apoptotic signal. Ultrastructural observations also revealed damaged organelles of gonadal cells in both testes and ovaries. Most of the hypothalamic-pituitary-gonadal (HPG) axis genes examined and serum sex steroid hormones tended to be downregulated after Cu exposure. Metabolomic analysis suggested that gonadal estradiol level is sensitive to Cu-NPs or CuSO4. The heat map of gonadal metabolomics suggested a similar effect of 200 µg Cu/L Cu-NPs and 100 µg Cu/L CuSO4 in both the ovaries and testes. Additionally, metabolomics data showed that the reproductive toxicity due to Cu-NPs and CuSO4 may occur via different metabolic pathways. Cu-NPs tend to dysregulate the metabolic pathways of sphingolipid and linoleic acid metabolism in the ovary and the biosynthesis of amino acids and pantothenate and CoA in the testis. Overall, these findings revealed the toxicological effects of Cu-NPs and CuSO4 on the HPG axis and gonadal metabolism in yellow catfish.

Target Enzyme-Triggered Click Chemistry and Hybridization Chain Reaction for Fluorescence Nonculture Homogeneous Analysis of E. coli in Bloodstream Infections.

Escherichia coli is the major pathogen that causes bloodstream infections (BSI). It is critical to develop nonculture identification methods which can meet the urgent need of clinical diagnosis and treatment. In this study, we reported a homogeneous fluorescence E. coli analysis system using ß-galactosidase (ß-Gal) as the biomarker and double-stranded DNA-templated copper nanoparticles (dsDNA-Cu NPs) as the signal output. The product of the enzymatic hydrolysis reaction, p-aminophenol (PAP), could reduce Cu2+ to Cu+, triggering the alkyne-azido cycloaddition reaction (CuAAC). Subsequently, the hybrid chain reaction (HCR) was initiated, producing the dsDNA template used to generate Cu NPs in situ. The system achieved a wide linear range for ß-Gal and E. coli 1-104 mU/L and 10-2-10 colony-forming unit (CFU)/mL, and a detection limit of 0.3 mU/L and 0.003 CFU/mL, respectively. 65 samples (45 blood and 20 urine) were collected to evaluate the clinical practicality. The results demonstrated remarkable area under the curve (AUC) values of 0.95 and 0.916 from uncultured urine and blood, respectively. It had 100% specificity and 83.3% sensitivity. The whole duration of the strategy was 3.5 h, which significantly reduced the turnaround time (TAT) and facilitated early BSI diagnosis to improve patients' prognosis. Our work had the potential to be an alternative to culture-based methods in clinics.

Efficient Dual-Function Catalyst: Palladium-Copper Nanoparticles Immobilized on Co-Cr LDH for Seamless Aerobic Oxidation of Benzyl Alcohol and Nitrobenzene Reduction.

Layered double hydroxides (LDHs) present exciting possibilities across various industries, ranging from catalytic applications to water remediation. By immobilizing nanoparticles, LDHs' characteristics and functionality can be enhanced, allowing for synergetic interactions that further expand their potential uses. A simple chemical method was developed to produce well-dispersed Pd-Cu NPs on a Co-Cr LDH support using a combination of in situ coprecipitation/hydrothermal and sol-immobilization techniques. The Pd-Cu@Co-Cr LDH catalysts was obtained, showing its catalytic activity in promoting the aerobic oxidation of alcohols and enabling the reduction of nitro-compounds through NaBH4 mediation. The physicochemical properties of the prepared catalyst were comprehensively investigated utilizing a range of analytical techniques, comprising FTIR, XRD, XPS, TGA, nitrogen adsorption isotherm, FESEM, and HRTEM-EDX. The findings showed the significance of immobilizing the bimetallic Pd-Cu nanoparticles on the Co-Cr LDH via an exceptional performance in the aerobic oxidation of benzyl alcohol (16% conversion, 99.9% selectivity to benzaldehyde) and the reduction of nitrobenzene (98.2% conversion, rate constant of 0.0921 min-1). The improved catalytic efficacy in benzyl alcohol oxidation and nitrobenzene reduction on the Pd-Cu@Co-Cr LDH catalyst is attributed to the uniform distribution and small size of the Pd-Cu NPs as active sites on the Co-Cr LDH surface. The prepared catalyst demonstrated exceptional stability during repeated runs. This study paves the way for multiple opportunities in tailoring, producing, and precisely controlling catalysts for various organic transformation reactions.

Metal nanoparticles against fungicide resistance: alternatives or partners?

Chemical control suffers from the loss of available conventional active ingredients due to strict environmental safety regulations which, combined with the loss of fungicide efficacy due to resistance development, constitute major problems of contemporary crop protection. Metal-containing nanoparticles (MNPs) appear to have all the credentials to be next-generation, eco-compatible fungicide alternatives and a valuable anti-resistance management tool. Could the introduction of MNPs as nano-fungicides be the answer to both reducing the environmental footprint of xenobiotics and dealing with fungicide resistance? The potential of MNPs to be utilized as nano-fungicides, both as alternatives to conventional fungicides or/and as partners in combating fungicide resistance, is discussed in terms of effectiveness, potential antimicrobial mechanisms as well as synergy profiles with conventional fungicides. However, their "golden" potential to be used both as alternatives and partners of conventional fungicides to combat resistance and reduce environmental pollution is challenged by undesirable effects towards non-target organisms such as phytotoxicity, toxicity to humans and environmental ecotoxicity, constituting risks that should be considered before their commercial introduction as nano-pesticides at a large scale. © 2022 Society of Chemical Industry.

Antifungal Activities of Sulfur and Copper Nanoparticles against Cucumber Postharvest Diseases Caused by Botrytis cinerea and Sclerotinia sclerotiorum.

Nanoparticles (NPs) have attracted great interest in various fields owing to their antimicrobial activity; however, the use of NPs as fungicides on plants has not been sufficiently investigated. In this study, the antifungal activities of sulfur nanoparticles (S-NPs) and copper nanoparticles (Cu-NPs) prepared by a green method were evaluated against Botrytis cinerea and Sclerotinia sclerotiorum. The formation of NPs was confirmed by transmission electron microscopy (TEM) and X-ray diffraction analysis (XRD). The antifungal activities of NPs (5-100 µg/mL), CuSO4 (4000 µg/mL), and micro sulfur (MS) were compared to those of the recommended chemical fungicide Topsin-M 70 WP at a dose of 1000 µg/mL. They were evaluated in vitro and then in vivo at different temperatures (10 and 20 °C) on cucumber (Cucumis sativus) fruits. The total phenolic content (TPC) and total soluble solids (TSS) were determined to study the effects of various treatments on the shelf life of cucumber fruits, compared to untreated cucumber as a positive control. The diameters of S-NPs and Cu-NPs ranged from 10 to 50 nm, and 2 to 12 nm, respectively. The results revealed that S-NPs exhibited the highest antifungal activity, followed by Cu-NPs. However, CuSO4 showed the lowest antifungal activity among all treatments. The antifungal activity of the prepared NPs increased with the increase in NP concentration, while the fungal growth was less at low temperature. The cytotoxicity of the prepared NPs was evaluated against the WI-38 and Vero cell lines in order to assess their applicability and sustainability. S-NPs caused less cytotoxicity than Cu-NPs.

Homogeneous two-dimensional visual and fluorescence analysis of circulating tumor cells in clinical samples via steric hindrance regulated enzymes recognition cleavage and elongation.

Oncology detection technology is significant for the early detection of tumors. The current study reports a new method that uses folate receptor (FR) as circulating tumor cells (CTCs) marker and only folate modified T30 as a probe. This method also uses dual-enzyme assisted amplification strategy for homogeneous fluorescence as well as two-dimensional visual (color and distance) detection of SMMC-7721 liver cancer cells from clinical blood samples. This work was based on the steric hindrance caused by binding between FR and folate to regulate cleavage of folate-T30 by exonuclease I (Exo I) and to inhibit subsequent polymerization and extension reaction of the cleavage product by terminal deoxynucleotidyl transferase (TdT). It explores the use of CdTe QDs to selectively identify Cu2+ and polyT-template Cu NPs as a bridge combined with inkjet printing technology to make test strips that can be read through distance changes. Under fluorometer mode, limit of detection as low as 1 cells/mL was achieved. The color and distance reading modes can identify cells with concentrations as low as 5 and 1 cells/mL, respectively. This CTCs detection approach of fluorescence mode was further validated by using 50 clinical samples of liver cancer patients (19 negative and 31 positive). The results were in good agreement with FR-polymerase chain reaction (FR-PCR) kits, radiologic and pathological techniques. In addition, the quantitative results of distance reading test strips of CTCs in 22 clinical samples (8 negative and 14 positive) were also in 100% agreement with the findings of clinical kits, computed tomography (CT) and pathological tests.

Fabrication of acid-resistant imprinted layer on magnetic nanomaterials for selective extraction of chlorogenic acid in Honeysuckle.

The common elution process of molecularly imprinted polymers (MIPs) is carried out in an acidic medium, which greatly affects the stability and reusability of synthetic MIPs, especially for magnetic MIPs. In this study, we fabricated an acid-resistant imprinted layer formed by phase-transitioned lysozyme on magnetic nanomaterials for selective extraction of chlorogenic acid in Honeysuckle, which often coexists with structural analogs. The newly designed acid-resistant imprinted layer can not only protect the internal magnetic core from denudation and dissolution, but also maintain the integrity of the imprinted layer during the elution process. The resultant magnetic MIPs exhibited good stability with no change on morphology after the repeatedly eluting process, and satisfactory reusability that can be used at least ten adsorption-desorption cycles with almost no decrease for adsorption capacity. In addition, the resultant materials possess satisfactory magnetism, uniform morphology with typical core-shell structure, stable crystallization, and good adsorption performance showing on high adsorption amount (10.82 mg g-1), fast kinetic equilibrium time (as short as 30 min), and satisfactory selectivity (IF = 2.85, SC > 1.5). At last, the obtained magnetic MIPs as adsorbents coupled with HPLC were successfully used to selective extract CGA in Honeysuckle samples with the high recoveries in the range of 92.0-104.4%, and the contents of CGA in Honeysuckle samples from the different origin are calculated in the range of 0.98%-1.24%.

Boosting the electrocatalytic activity of Pd/C by Cu alloying: Insight on Pd/Cu composition and reaction pathway.

Tuning composition of Pd-based bimetallic electrocatalysts of high stability and durability is of great importance in energy-related reactions. This study reports the remarkable electrocatalytic performance of carbon-supported bimetallic Pd-Cu alloy nanoparticles (NPs) towards formic acid oxidation (FAO) and oxygen reduction reaction (ORR). Among various bimetallic compositions, Pd3Cu/C alloy NPs exhibits the best FAO and ORR activity. During FAO reaction, Pd3Cu/C alloy NPs exhibits a peak with a current density of 28.33 mA cm-2 and a potential of 0.2 V (vs. Ag/AgCl) which is higher than that of the other PdCu compositions and standard 20 wt% Pd/C catalyst. Meanwhile, the onset potential (-0.09 V), half-wave potential (-0.18 V), limiting current density at 1600 rpm (-4.9 mA cm-2) and Tafel slope (64 mV dec-1) values of Pd3Cu/C alloy NPs validate its superiority over the conventional 20 wt% Pt/C catalyst for ORR. Experimental and DFT studies have confirmed that the enhanced activity can be attributed to the electronic effect that arises after Cu alloying which causes a downshift of Pd d-band center and structural effect that produces highly dispersed NPs over the carbon matrix with high electrochemically active surface area.