High Anti-interference Ability Research Articles

Two robust dual-functional Cd(II) MOFs as luminescent sensors for quantitatively detection of nitrofurazone and Fe3+ ions

Developing luminescent sensors based metal organic framework (MOFs) for the detection of antibiotics and metal ions is still a major challenge. The two new ternary Cd(II)-based MOFs, namely, {[Cd(BTA)0.5(L)0.5]n} (1) and {[Cd(HBTC)(L)]n} (2) (H4BTA = 1,2,4,5-benzenetetracarboxylic acid, H3BTC = 1,2,4-benzenetricarboxylic acid, and L = 1,4-bis(2-((1H-imidazol-1-yl)methyl)-1H-benzo[d]imidazol-1-yl)but‑2-ene), were hydrothermally synthesized and characterized. 1 displays a 4,4-connected sqc183 topological framework with point symbol {42.84}, while 2 exhibits a 4,5-connected sqc65 framework with point symbol {42.64}{43.67}2. Both 1 and 2 display remarkable luminescence emission and enable selective detection of NFZ and Fe3+ ions with high anti-interference ability as well as excellent thermal and pH stability. The limits of detection (LOD) of 1 and 2 for nitrofurazone (NFZ) are 4.5 × 10−7 mol·L−1 and 9.0 × 10−7 mol·L−1, respectively. The LOD toward Fe3+ for 1 is 1.4 × 10−5 mol·L−1, for 2 is 6.2 × 10−6 mol·L−1. To the best of our knowledge, this is the first example of MOFs bearing L ligands as dual-functional luminescent sensors for sensing NFZ and Fe3+ ions. In addition, the mechanism of luminescence quenching was investigated.

Electrochemical detection of acetaminophen and caffeine using Ag nanoparticles doped metal-organic framework (ZIF-67) composites

The combination of metal organic framework (MOFs) with metal nanoparticles has great prospects for improving the electrochemical property of sensors. In this paper, silver (Ag) nanoparticles doping Co-based zeolitic imidazolate framework (ZIF-67) composites (Ag-ZIF-67) were prepared by ultrasonic treatment of ZIF-67 and reduction of metal precursor (AgNO3) in ZIF-67 material. Ag-ZIF-67 nanosheet material was obtained and characterized by transmission electron microscopy and electrochemical impedance spectroscopy. Due to the synergistic effect of high porosity and large specific surface area of ZIF-67, as well as the high electrical conductivity and prominent catalytic activity of Ag nanoparticles, Ag-ZIF-67 modified glassy carbon electrode showed excellent electrocatalytic activity for the detection of acetaminophen (AP) and caffeine (CAFF), including wide linear range (0.1–70.0 μM) for AP and (0.5–300.0 μM) for CAFF, high anti-interference ability. Additionally, the prepared Ag-ZIF-67 sensor also exhibited excellent selectivity for two compounds detection and prospective results in pharmaceutical formulations samples.

Nanoarchitectonics of on–off ratiometric signal amplified electrochemical sensor for chlorpromazine with molecularly imprinted polymer based on Ni-MOF/Fe-MOF-5 hybrid Au nanoparticles

A novel and stable on–off ratiometric electrochemical sensing platform for chlorpromazine (CPZ) detection by combing the selective recognition of molecularly imprinted polymer (MIP) technology and ratiometric quantification strategy. Gold nanoparticles (AuNPs) were first electrodeposited on a bare glassy carbon electrode surface and then modified with a mixture of Ni-MOF/Fe-MOF-5 by drop-coating, and subsequently electropolymerization polythionine (pTHi) as an internal reference to achieve a ratiometric on–off response. The reference signal of pTHi was obtained by the boiling water-bath-assisted in-situ electropolymerization method for the first time. Ni-MOF/Fe-MOF-5 hybrid AuNPs (Ni-MOF/Fe-MOF-5/AuNPs) not only benefited the output signal amplification, but also provided the enlarged surface for immobilization of pThi and MIPs, and served as catalytic active centers to oxidation CPZ. Then, the MIPs membrane was fabricated through in-situ electropolymerization by using CPZ as the template molecule, nicotinamide as a functional monomer. Ratiometric identifying and quantitative sensing model has been proposed based on the combination of MIP membrane as molecular recognition receptor and pTHi used as an internal reference probe, which improves the sensitivity and selectivity of the sensor. Under the optimal conditions, the ratiometric signals of peak current (ICPZ/IpTHi) were linear to CPZ concentration in the range of 0.001–40 μM and 40–900 μM, with the ultralow detection limit of 0.025 μM (S/N = 3). Furthermore, this sensor exhibited high anti-interference ability, reproducibility, satisfactory stability, and outstanding measurement performance in biological samples with favorable recoveries in the range of 98.11–100.81%. Together, the constructed on–off ratiometric MIP sensing platform is a promising tool for the rapid and accurate determination of antipsychotic drugs with high selectivity and stability.

Synthesis of Graphene Oxide-Coupled CoNi Bimetallic MOF Nanocomposites for the Simultaneous Analysis of Catechol and Hydroquinone.

Herein, a three-dimensional flower-like cobalt-nickel bimetallic metal-organic framework (CoNi-MOF) coupled with two-dimensional graphene oxide (GO) nanocomposites was successfully synthesized for the selective and simultaneous electrochemical determination of catechol (CC) and hydroquinone (HQ). The three-dimensional flower-like structure of the CoNi-MOF/GO nanocomposite has a multilayer structure and a large surface area, which greatly improves its electrocatalytic activity towards CC and HQ. Differential pulse voltammetry (DPV) results showed that the peak-to-peak separation of CC (0.223 V) and HQ (0.120 V) was 103 mV at a CoNi-MOF/GO modified glassy carbon electrode (CoNi-MOF/GO/GCE), suggesting that the proposed modified electrode can selectively and simultaneously determine them. Under optimal conditions, the CoNi-MOF/GO/GCE showed an excellent analytical performance for the simultaneous determination of CC and HQ, including a wide linear range (0.1-100 μM), low detection limit (0.04 μM for HQ and 0.03 μM for CC) and high anti-interference ability. As expected, the developed modified electrode has been used to analyze CC and HQ in river water, with acceptable results.

Cellulose/amylose derivatives bearing bulky substituents as reversible fluorescent sensors for detection of Fe3+

Two novel cellulose and amylose derivatives bearing bulky tris(2-benzothienylformate) pendants (Cel-3 and Amy-3) were expeditiously prepared by one-step esterification. The fluorescent sensing performance of six polysaccharide derivatives, including Cel-3/Amy-3, and other four previously prepared benzothienyl- or benzofuranyl-phenylcarbamates of cellulose and amylose (Cel-1/Amy-1, Cel-2/Amy-2), were carefully evaluated using eight metal ions, including Co2+, K+, Na+, Li+, Hg2+, Ni2+, Ca2+ and Fe3+. All six derivatives exhibited excellent fluorescence quenching property to Fe3+ ions with high sensitivity and selectivity. Especially, the limit of detection of Amy-2 with benzofuranylphenylcarbamates for Fe3+ was 3.0 μM, much lower than the maximum contaminant level for Fe3+ in the drinking water. Additionally, the six bulky derivatives displayed the interesting fluorescence “turn-off” and “turn-on” observation, indicating a desirable reversibility for Fe3+ detection. The high anti-interference ability was also observed for detection of Fe3+ on the benzothienyl/benzofuranyl derivatives of cellulose and amylose in the combined system containing Co2+, K+, Na+, Li+, Hg2+, Ni2+ and Ca2+. It suggested that the obtained polysaccharide derivatives with bulky chromophores possessed good potentials for detection of Fe3+ as high-efficient fluorescent sensors in diverse applications. The sensing mechanism for detection of Fe3+ was further proposed based on the Stern-Volmer plots and fluorescence titration analysis.

Comparison of UNB-based LPWAN Networks

Internet of things (IoT) technology has been a hot research direction in recent years. Low Power Wide Area Network (LPWAN) is an important part of IoT. It helps realize smart cities, guarantees logistics security, and food security. It has important applications in both industrial and agricultural fields. Ultra narrow band (UNB) are systems that have very high spectrum efficiency but with restricted communication rate. It has become a popular choice for LPWAN due to its high anti-interference ability and low energy consumption. Therefore, in recent years, many LPWANs based on UNB technology have been developed. This paper introduces UNB, LPWAN, and IOT technologies in detail, and explains how LPWAN and UNB are used in IoT technologies. Then three UNB-based LPWAN networks, Sigfox, Telensa, Weightless-N, are introduced. Finally, we will compare these three technologies in terms of system composition, performance and application to find out their advantages and disadvantages in different aspects.

Insights into the Effect of Cation Distribution at Tetrahedral Sites in ZnCo2O4 Spinel Nanostructures on the Charge Transfer Ability and Electrocatalytic Activity toward Ultrasensitive Detection of Carbaryl Pesticide in Fruit and Vegetable Samples

The recent advancement in designing novel spinel nanostructures has opened virtually infinite possibilities for the development of high-performance electrochemical sensors to detect target species. The electrocatalytic activity of spinel structures can be enhanced by tuning the cation distribution; however, the role of cation distribution at tetrahedral ions on the electrochemical sensing responses has rarely been considered. Herein, the effect of cation distribution at tetrahedral sites (Td) in the spinel nanostructure ZnCo2O4 on the electrochemical sensing performance toward carbaryl (CBR) was first investigated. The ZnCo2O4 nanoflake samples with different cation ratios of Zn/Co at tetrahedral sites were designed by using a facile solvothermal method. We found that a higher Zn ion content at tetrahedral sites significantly enhanced the electron transfer ability through the electrolyte/electrode interface. More interestingly, a higher Co ion ratio between octahedral sites and tetrahedral (CoOh/CoTd) promoted the electrochemical oxidation process of CBR with a higher catalytic rate constant (kcat). Under optimized conditions, the ZnCo2O4-NF-based electrochemical nanosensor showed a linear response from 0.15 to 100 μM with a limit of detection of 0.05 μM and a high electrochemical sensitivity of 2.04 μA μM–1cm–2. The designed nanosensor also exhibited good repeatability, long-time stability, high anti-interference ability, and excellent recovery with fruit and vegetable samples. Furthermore, this study offers insights into the cation distribution-dependent electrocatalytic activities of spinel nanostructures, which is helpful to the design of advanced spinel nanostructure-based electrocatalysts for improving the electrochemical sensing performance.

Construction of a novel ESIPT and AIE-based fluorescent sensor for sequentially detecting Cu2+ and H2S in both living cells and zebrafish

The development of effective methods for tracking Cu2+ and H2S in living organisms is urgently required due to their vital function in a variety of pathophysiological processes. In this work, a new fluorescent sensor BDF with excited-state intramolecular proton transfer (ESIPT) and aggregation-induced emission (AIE) features for the successive detection of Cu2+ and H2S was constructed by introducing 3,5-bis(trifluoromethyl)phenylacetonitrile into the benzothiazole skeleton. BDF showed a fast, selective and sensitive fluorescence “turn off” response to Cu2+ in physiological media, and the situ-formed complex can serve as a fluorescence “turn on” sensor for highly selective detection of H2S through the Cu2+ displacement approach. In addition, the detection limits of BDF for Cu2+ and H2S were determined to be 0.05 and 1.95 μM, respectively. Encouraged by its favourable features, including strong red fluorescence from the AIE effect, large Stokes shift (285 nm), high anti-interference ability and good function at physiological pH as well as a low toxicity, BDF was successfully applied for the consequent imaging of Cu2+ and H2S in both living cells and zebrafish, making it an ideal candidate for detecting and imaging of Cu2+ and H2S in live systems.

Indoor Visible-Light 3D Positioning System Based on GRU Neural Network

With the continuous development of artificial intelligence technology, visible-light positioning (VLP) based on machine learning and deep learning algorithms has become a research hotspot for indoor positioning technology. To improve the accuracy of robot positioning, we established a three-dimensional (3D) positioning system of visible-light consisting of two LED lights and three photodetectors. In this system, three photodetectors are located on the robot’s head. We considered the impact of line-of-sight (LOS) and non-line-of-sight (NLOS) links on the received signals and used gated recurrent unit (GRU) neural networks to deal with nonlinearity in the system. To address the problem of poor stability during GRU network training, we used a learning rate attenuation strategy to improve the performance of the GRU network. The simulation results showed that the average positioning error of the system was 2.69 cm in a space of 4 m × 4 m × 3 m when only LOS links were considered and 2.66 cm when both LOS and NLOS links were considered with 95% of the positioning errors within 7.88 cm. For two-dimensional (2D) positioning with a fixed positioning height, 80% of the positioning error was within 9.87 cm. This showed that the system had a high anti-interference ability, could achieve centimeter-level positioning accuracy, and met the requirements of robot indoor positioning.

Joule heating-assisted tailoring Co-MOC derived chainmail catalyst to regulate peroxymonosulfate activation for tetracycline destruction: Singlet oxygen integrated direct electron transfer pathways

Rational design of stable and high-efficiency non-precious catalysts to activate peroxymonosulfate (PMS) is crucially important for recalcitrant pollutant elimination. In this study, we present a microwave-assisted combustion heat method to fabricate stable Co-MOC-800 as a highly efficient peroxymonosulfate (PMS) activator for tetracycline hydrochloride (TCH) degradation. Joule heating from short-time microwave irradiation enables the expeditious fabrication of Co-based metal–organic-complex (Co-MOC) precursor, which is carbonized to form the representative Co-MOC-800 chainmail catalyst with a maximum degradation rate of 97% in 10 min. This catalyst still possesses an excellent stability with highly remained activity of the initial cycle after five consecutive runs. The N-doped amorphous carbon encapsulated Co nanoparticles integrated Co-Nx sites play an essential role in activating PMS for TCH degradation through non-radial dominant pathways including singlet oxygen and direct electron transfer. Attributing to the non-radical pathways, the Co-MOC-800-catalyzed PMS activation exhibits relatively high anti-interference ability under different solution pH, inorganic anions and humic acid. Three reaction pathways for TCH degradation are proposed by recording the degradation intermediates, and the toxicity of the detected intermediates was evaluated. The present work provides a vivid example for simply fabricating efficient Co-based catalysts for recalcitrant pollutant elimination via activating PMS.

Amine functionalization of iron-based metal-organic frameworks MIL-101 for removal of arsenic species: Enhanced adsorption and mechanisms

Chronic exposure to inorganic arsenic (As)-contaminated water seriously threatens human health. Although iron-based metal-organic frameworks (MOFs) for arsenic removal have been developed, their practical application has been challenging due to their lack of binding sites and low stability. In this study, we attempted to improve the arsenic adsorption capacity of MIL-101(Fe) in water by amine functionalization. NH2-MIL-101(Fe) was synthesized using a facile solvothermal method. It adsorbed > 70 % arsenate (As (V)) throughout a wide pH range of 4–9, exhibited high anti-interference ability and reusability, and effectively eliminated arsenic from contaminated river samples, demonstrating its great potential in As-polluted water treatment. Best adsorption effectiveness at pH 7 indicated that the electrostatic attraction between -NH2 and As (V) was not its primary adsorption mechanism. Instead, FTIR and XPS analyses revealed that the complexation between Fe and As was the key mechanism. NH2-MIL-101(Fe) had substantially better As (V) and arsenite (As (III)) adsorption capacities (147.7 mg/g and 153.4 mg/g, respectively) than MIL-101(Fe) (82.8 mg/g and 131.2 mg/g, respectively). This is because amine modification increased the Fe content and Fe3+/Fe2+ ratio, as well as the specific surface area and pore volume. This research elucidates how amine modification affects the ability of Fe-MOFs to adsorb arsenic.

A novel high-stability bioelectrochemical sensor based on sol-gel immobilization of lactate dehydrogenase and AuNPs-rGO signal enhancement for serum pyruvate detection

Pyruvate participates in diverse metabolic pathways in the body and is normally present in human blood at 40–120 μM, with concentrations outside this range associated with various diseases. Therefore, accurate and stable blood pyruvate level tests are necessary for effective disease detection. However, traditional analytical techniques require complicated instrumentation and are time consuming and expensive, prompting researchers to develop improved methods based on biosensors and bioassays. Here, we designed a highly stable bioelectrochemical pyruvate sensor affixed to a glassy carbon electrode (GCE). To maximize biosensor stability, 0.1 U of lactate dehydrogenase was affixed to the GCE using a sol-gel process, resulting in generation of Gel/LDH/GCE. Next, 2.0 mg/mL AuNPs-rGO was added to enhance current signal strength, resulting in generation of the bioelectrochemical sensor Gel/AuNPs-rGO/LDH/GCE. AuNPs-rGO synthesized in advance was verified as correct using transmission electron microscopy and UV–Vis, Fourier-transform infrared and X-ray photoelectron spectroscopy. Pyruvate detection conducted via differential pulse voltammetry in phosphate buffer (pH 7.4, 100 mM) at 37 °C for 1–4500 μM pyruvate provided detection sensitivity as high as 254.54 μA/mM/cm2. The reproducibility, regenerability and storage stability were analyzed with the relative standard deviation of 5 bioeletrochemical sensors detection was 4.60% and biosensor accuracy after 9 cycles was 92%, with accuracy remaining at 86% after 7 days. In the presence of D-glucose, citric acid, dopamine, uric acid and ascorbic acid, the Gel/AuNPs-rGO/LDH/GCE sensor exhibited excellent stability, high anti-interference ability and better performance than conventional spectroscopic methods for detection of pyruvate in artificial serum.

Effects of functional group loss on biochar activated persulfate in-situ remediation of phenol pollution in groundwater and its countermeasures

Biochar is considered a good activator for use in advanced oxidation technology. However, dissolved solids (DS) released from biochar cause unstable activation efficiency. Biochar prepared from saccharification residue of barley straw (BC-SR) had less DS than that prepared directly from barley straw (BC–O). Moreover, BC-SR had a higher C content, degree of aromatization, and electrical conductivity than BC-O. Although the effects of BC-O and BC-SR on activation of Persulfate (PS) to remove phenol were similar, the activation effect of DS from BC-O was 73% higher than that of DS from BC-SR. Moreover, the activation effect of DS was shown to originate from its functional groups. Importantly, BC-SR had higher activation stability than BC-O owing to the stable graphitized carbon structure of BC-SR. Identification of reactive oxygen species showed that SO4•-, •OH, and 1O2 were all effective in degradation by BC-SR/PS and BC-O/PS systems, but their relative contributions differed. Furthermore, BC-SR as an activator showed high anti-interference ability in the complex groundwater matrix, indicating it has practical application value. Overall, this study provides novel insight that can facilitate the design and optimization of a green, economical, stable, and efficient biochar-activated PS for groundwater organic pollution remediation.

MOFs-derived core-shell structured NiCo2O4NWs@Co3O4NPs for non-enzymatic glucose detection

Metal-organic frameworks (MOFs) exhibit many structural advantages, such as large specific surface area and abundant active sites, which make them promising candidates as electrode materials for non-enzymatic glucose sensors. In this work, using MOFs as templates, MOFs derived Co3O4 nanoparticles (NPs) were in-situ synthesized on the surface of NiCo2O4 nanowires (NWs), forming a self-supporting electrode based on nickel foam (NF), which was directly used for the detection of glucose. Because of the presence of MOFs derivatives and self-supporting structures, NF/NiCo2O4NWs@Co3O4NPs electrode exhibits good structural stability and high conductivity, which ensure the excellent electrocatalytic performance. The NF/NiCo2O4NWs@Co3O4NPs electrode shows prominent electrocatalytic performance toward glucose with a wide testing range (0.001–1.7 mmol/L), high sensitivity (8163.2 μA cm−2 mM−1), fast response time (within 1 s), high anti-interference ability and long-term stability. Further, the electrode was used to test different glucose levels in live mouse serum samples, showing acceptable reliability and high accuracy comparing with blood glucose meter test (medical test method). Thus, NF/NiCo2O4NWs@Co3O4NPs electrode with self-supporting core-shell nanostructure will be a promising candidate applied in non-enzymatic glucose sensors.

Sensitive photoelectrochemical immunosensor for carcinoembryonic antigen detection based on copolymer of thiophene and thiophene-3-acetic acid modified phosphate-doped Bi2WO6

In this study, PO43− doped Bi2WO6 (BWO-PO) was prepared by hydrothermal method, and then copolymer of thiophene and thiophene-3-acetic acid (P(Th-T3A)) was chemically deposited on the BWO-PO surface. The introduction of PO43− created point defects, greatly improving the photoelectric catalytic performance of Bi2WO6; the copolymer semiconductor could form heterojunction with Bi2WO6 to promote the separation of photo-generated carriers, due to its proper band gap. Furthermore, the copolymer could enhance the light absorption ability and photo-electronic conversion efficiency. Hence, the composite had good photoelectrochemical properties. When it was combined with carcinoembryonic antibody through the interaction of –COOH groups of the copolymer and the end groups of antibody for constructing ITO-based PEC immunosensor, the resulting sensor exhibited superb response to carcinoembryonic antigen (CEA), with a wide linear range of 1 pg/mL−20 ng/mL, and a relatively low detection limit of 0.41 pg/mL. It also showed high anti-interference ability, stability, and simplicity. The sensor has been successfully applied to monitor the concentration of CEA in serum. The sensing strategy can also be applied to the detection of other markers by changing the recognition elements, hence it has good application potential.

New strategy to remove phosphate from low concentration solution by MOFs-modified resin: High affinity and thermal desorption

Adsorption process was usually torn between higher affinity and easier regeneration. Herein, for removing phosphate from low concentration solution, a new strategy was developed to break this tradeoff by metal organic frameworks (MOFs) confined in resins. For comparison, a series of metal oxide modified resins were prepared as adsorbents together with MOFs modified resins (transformation from corresponding oxides). MIL-101(Fe) presents higher adsorption capacity (41.79 mg/g) than Oxide(Fe)@201(36.07 mg/g), as well as high anti-interference ability with removal efficiency of 99.8% (2 mg/L phosphate), even if the loading amounts of iron in Oxide(Fe)@201 is almost twice of that in MIL-101(Fe)@201. Instrumental analysis and molecular dynamics simulations show that the higher adsorption affinity is mainly due to direct interaction between Fe3+ and phosphate via the formation of Fe-O-P, leading to much lower adsorption binding energy (Eads) of phosphate on MIL-101(Fe)@201 (-42.48 kcal/mol) than Oxide(Fe)@201; In desorption process, the MOFs structure can be stably restored with push of organic salt and high temperature (60 °C) around neutral pH due to the reversible structural transformation of MOFs. Moreover, MIL-101(Fe)@201 can continuously purify wastewater containing low concentration phosphate in fixed bed system after multiple regeneration, the water treatment capacity remained above ∼3000 BV and the regenerants can be intermittently recycled with precipitation of calcium phosphate from the solutions.

A light-up fluorescence platform based DNA: RNA hybrid G-quadruplet for detecting single nucleotide variant of ctDNA and miRNA-21

The nucleic acid assay is an area of great concern in the diagnosis and treatment of breast cancer. Here, we developed a DNA: RNA hybrid G-quadruplet (HQ) detection platform based on strand displacement amplification (SDA) and Baby Spinach RNA aptamer for single nucleotide variant (SNV) of circulating tumor DNA (ctDNA) and miRNA-21. This was the first in vitro construction of HQ for the biosensor. It found that HQ had much stronger ability to switch on fluorescence of DFHBI-1T than Baby Spinach RNA alone. Taking advantage of the platform and the FspI enzyme with high specificity, the biosensor achieved ultra-sensitive detection of SNV of the ctDNA (PIK3CA H1047R gene) and miRNA-21. The light-up biosensor had high anti-interference ability in complex actual samples. Hence, the label-free biosensor provided a sensitive and accurate method for early diagnosis of breast cancer. Moreover, it opened a new application model for RNA aptamers.

Clinical performance evaluation of serum amyloid A module of Mindray BC-7500CS automated hematology analyzer.

Laboratory detection of high values of serum amyloid A (SAA) is impaired by the hook effect. In response to this problem, Mindray has launched the new generation BC-7500CS automated hematology analyzer with an SAA autodilution (SAA-D) function. The present study aimed to verify the performance of the SAA module. Venous whole-blood specimens anticoagulated with EDTA-K2 were randomly collected from outpatients and inpatient of the Children's Hospital of Nanjing Medical University (CH). Background, repeatability, precision, linear range, intermode comparison, and interference of the SAA module of the Mindray BC-7500CS were evaluated, and the performance of the SAA-D function was verified. The Mindray BC-7500CS showed an SAA background of 0.14 mg/L, well below that claimed by the manufacturer. Repeatability of SAA with standard deviation (SD) <0.6 mg/L and coefficient of variation (CV) <6%, the quality control (QC) precision was less than 8%. The measured value of the linear range was essentially consistent with the theoretical value, and the maximum measured values could reach 1932.38 mg/L. The deviation between whole-blood mode and micro-whole-blood mode was small (r=0.999), and the SAA module displayed high anti-interference ability. In addition, the measured results of specimens with high SAA concentration diluted by SAA-D were close to those after manual dilution (r=0.993). The SAA module of the Mindray BC-7500CS had excellent performance, and the SAA-D function was highly accurate at measuring specimens with high SAA concentration, enabling reliable SAA detection in the laboratory and clinical practice.

Macroporous honeycomb-like magnesium oxide fabricated as long-life and outstanding Pb(II) adsorbents combined with mechanism insight.

The macroporous honeycomb-like MgO (MHM) had been successfully prepared by hard template method using polystyrene (PS) spheres with different particle sizes of about 400, 600, and 800nm, respectively. The adsorption performance (3700, 3470, and 3087mg/g) and specific surface areas (64.0, 51.4, and 34.4 m2/g) of MHM materials were inversely proportional to their pore diameters. Among the prepared MHM materials, MHM-400 exhibited the most excellent adsorption performance of 3700mg/g towards Pb(II) at 25°C. In this study, the macropore size in MHM played a major role in the adsorption process; Dubinin-Radushkevich (D-R) model further indicated that Pb(II) removal by MHM-400 was dominated by chemical adsorption. The thermodynamic analysis (ΔG0 < 0, ΔH0 > 0, and ΔS0 > 0) revealed that the Pb(II) adsorption was spontaneous and endothermic. After storing for 360days, the Pb(II) removal efficiency of MHM-400 was still higher than 98.2%, exhibiting ultra-long life for Pb(II) capture. MHM-400 also exhibited high anti-interference ability towards typically coexisting ions (Na+ and K+). According to the density functional theory (DFT) calculation, the Pb could be adsorbed on the top site of the oxygen atom at the surface of the cubic MgO (200) plane; the adsorption energy (Ead) was 0.159eV. The XRD and FTIR analyses revealed the further formation of Pb3(CO3)2(OH)2 and PbO after Pb(II) adsorption. Furthermore, MHM-400 could effectively remove both Cd(II) and Pb(II) ions from wastewater within 20min, and the adsorption efficiency achieved > 99%, suggesting that MHM-400 was a potential material for effective Pb(II) removal.

Novel Green Fluorescent Probe Stem From Carbon Quantum Dots for Specific Recognition of Tyrosinase in Serum and Living Cells.

Tyrosinase (TYR), an important biomarker for melanoma, offered significant information early detection of melanoma and may decrease the likelihood of mortality. Therefore, this article constructed a highly sensitive and selective green fluorescent functionalized carbon quantum dots (TYR-CQDs) for tyrosinase (TYR) activity detection by one-step hydrothermal protocol utilizing catechol, citric acid and urea as precursors. The prepared TYR-CQDs illustrated excellent linear relationship and broad linear range with a low detection limit, which exhibited high accuracy and recovery in quantitative determination of TYR in human serum samples. Furthermore, the TYR-CQDs had successfully realized intracellular TYR detection owing to excellent biocompatibility, high anti-interference ability and good cellular imaging capability, suggesting the potential biomedical applications in early diagnosis of melanoma and other tyrosinase-related diseases.