Highly stable benzonitrile functionalized covalent organic framework coating for solid-phase microextraction of hydroxyphenyl esters in complex matrix samples.

A mesoporous surface benzonitrile functionalized covalent organic framework (TpBD-CN-COF) was synthesized as a novel solid-phase microextraction (SPME) fiber coating for the extraction of six hydroxyphenyl esters (PBs), and combined with gas chromatography-flame electric-ion detector (GC-FID). PBs were sensitively determined in aqueous solution. Due to its high specific surface area, high chemical stability in both strongly acidic and alkaline media, and in polar or non-polar media, as well as its high thermal stability, the TpBD-CN-COF fiber coating showed excellent extraction performances for PBs with an enrichment factor twice as high as that of TpBD-COF.

The study on effects of acute exposure to high altitude hypoxia on cognitive function in lowlander.

The investigation of cognitive functions in response to high-altitude exposure has garnered increasing scientific interest. However, it remains unclear whether cognitive abilities are selectively impaired or what are the trends of the function. In this study, we examined the effects of acute exposure to 3800 m on cognition among 20 lowlanders (27.

[Effects of Different Treatment Methods on the Contents of Related Growth Factors Released by Platelet Rich Plasma].

Objective: To evaluate the effect of sonication, repeated freeze-thaw cycles, calcium salt solution and their combination on the content of related growth factors (GFs) released by platelet rich plasma (PRP).

Methods: Twenty PRPs from healthy blood donors were divided into 9 groups, including sonication group, freeze-thaw group, calcium gluconate group, calcium chloride group, sonication + calcium gluconate group, sonication + calcium chloride group, freeze-thaw + calcium gluconate group, freeze-thaw + calcium chloride group, and sonication + freeze-thaw group. After PRP activated by above 9 methods, the content of transforming growth factor-β1 (TGF-β1), vascular endothelial growth factor (VEGF), and platelet-derived growth factor-BB (PDGF-BB) were detected by ELISA.

In Situ Synthetic ZIF-8/Carbon Aerogel Composites as Solid-Phase Microextraction Coating for the Detection of Phthalic Acid Esters in Water Samples.

In this study, a hybrid composite featuring zeolitic imidazolate framework-8/carbon aerogel (ZIF-8/CA) was synthesized via in situ nucleation and growth of ZIF-8 nanoparticles inside carbon aerogels. The novel material was used as the solid-phase microextraction (SPME) coating for the five phthalic acid esters (PAEs) detection by coupling with a gas chromatography-flame ionization detector (GC-FID). Compared with bare carbon aerogel, the ZIF-8/CA presented the best performance, which is attributed to the unique advantages between the high surface area of CA and high hydrophobic properties, the thermal stability of ZIF-8, and their synergistic adsorption effects, such as molecular penetration, hydrogen bond, and π-π stacking interactions.

Recyclable magnetic FeO@C for methylene blue removal under microwave-induced reaction system.

The reclamation and removal of organic pollutants are difficult issues of world concern. In this study, a microwave-induced reaction system (MIRS) is applied to synthesize the multifunctional composite of FeO@C, which is employed to adsorb, separate and catalytic oxide the typical organic dye of methylene blue (MB). SEM, TEM, VSM, XPS, pHpzc, and N adsorption performances are carried out to characterize the FeO@C.

Efficient Reduction of Cr(VI) with Carbon Quantum Dots.

Hexavalent chromium (Cr(VI)) pollution is a global problem, and the reduction of highly toxic Cr(VI) to less toxic Cr(III) is considered to be an effective method to address Cr(VI) pollution. In this study, low-toxicity carbon quantum dots (CQDs) were used to reduce Cr(VI) in wastewater. The results show that CQDs can directly reduce Cr(VI) at pH 2 and can achieve a reduction efficiency of 94% within 120 min.

Simultaneous Oxidation and Sequestration of Arsenic(III) from Aqueous Solution by Copper Aluminate with Peroxymonosulfate: A Fast and Efficient Heterogeneous Process.

The major problem in arsenic (As(III)) removal using adsorbents is that the method is time-consuming and inefficient owing to the fact that most of the adsorbents are more effective for As(V). Herein, we report a new discovery regarding the significant simultaneous oxidation and sequestration of As(III) by a heterogeneous catalytic process of copper aluminate (CuAlO) coupled with peroxymonosulfate (PMS). Oxidation and adsorption promote each other.

Synchronous oxidation and sequestration for As(iii) from aqueous solution by modified CuFeO coupled with peroxymonosulfate: a fast and stable heterogeneous process.

Bifunctional heterogeneous catalytic processes for highly efficient removal of arsenic (As(iii)) are receiving increased attention. However, the agglomerated nature and stability of nanoparticles are major concerns. Herein, we report a new process regarding the anchoring of CuFeO nanoparticles on a substrate material, a kind of Fe-Ni foam, to form porous CuFeO foam (CuFeO-foam) by synthesis.

Carboxylation modified meso-porous carbon aerogel templated by ionic liquid for solid-phase microextraction of trace tetracyclines residues using HPLC with UV detection.

A carbon aerogel composite templated and catalyzed by ionic liquid was fabricated to obtain a meso-porous and cross-linked structure while avoiding the freeze and supercritical drying. It was then carboxylated to obtain favorable surface groups. The easily prepared material displayed excellent extraction effect of six tetracyclines (TCs) compared to the non-carboxylated carbon aerogel.

Carbon aerogel as a solid-phase microextraction fiber coating for the extraction and detection of trace tetracycline residues in food by coupling with high-performance liquid chromatography.

A direct immersion solid-phase microextraction method for determining tetracyclines (TCs) was developed by coupling with high-performance liquid chromatography. A carbon aerogel (CA) was synthesized as a fiber coating with high extractive properties and a low density of 0.1855 g cm-3via ambient pressure drying and carbonization.

Data for a new spinel catalyst to activate peroxymonosulfate for highly efficient degrading organic contaminants in water based on non-radical process.

The aim of this research is to degrade organic contaminants in aqueous solution via lead ferrite (PbFeO) as a catalyst to activate peroxymonosulfate (PMS). PbFeO was synthesized by a citrate combustion method and analyzed by SEM, TEM and XRD. A simulated solution including thionine were used, with different conditions tested to optimize the degradation process, including comparing PbFeO to other catalysts, PbO and FeO, and tracking active oxygen species.

New insight into the mechanism of peroxymonosulfate activation by nanoscaled lead-based spinel for organic matters degradation: A singlet oxygen-dominated oxidation process.

Crystalline iron-based nanoparticles with spinel structure have received great attention for catalyzing peroxymonosulfate (PMS). This study introduces lead ferrite (PbFeO) as a novel, simple, and efficient catalyst to activate PMS for the degradation of organic contaminants in aqueous solution. The results indicated that, under pH 9.

Label-free analytical performances of a peptide-based QCM biosensor for trypsin.

A label-free biosensor was fabricated for the detection of trypsin by using a peptide-functionalized quartz crystal microbalance gold electrode. The synthetized peptide chains were immobilized tightly on the QCM electrode via a self-assembly method, which formed a thin and approximate rigid layer of peptides. The detection signal was achieved by calculating the mass changes on the QCM electrode because the peptide chains could be specifically cleaved in the carboxyl terminuses of arginine and lysine by trypsin.

A fluorescence sensing platform of theophylline based on the interaction of RNA aptamer with graphene oxide.

RNA, with a structure similar to DNA, should exhibit similar behaviors when it interacts with graphene. In this work, we designed a sensing platform of theophylline based on the interaction of an RNA aptamer with graphene oxide (GO) using the fluorescence as a sensing signal. Firstly, quantum dots (QDs) were modified with the selected ssRNA that can be used as an aptamer to recognize the theophylline.

[Coagulation Properties for Whole Blood Stored at 4℃].

Objective: To study the coagulation properties the refrigerated whole blood stored at 4℃.

Methods: Ten units of whole blood were obtained from healthy volunteer donors and stored at 4±2℃ for 21 days. Samples were collected on the day after donation and on days 2, 4, 6, 8, 10, 14 and 21 for delection including complete blood count, electrolyte, APTT, PT, Fg, blood coagulation factors, and thromboelastography(TEG).

Amplified QCM biosensor for type IV collagenase based on collagenase-cleavage of gold nanoparticles functionalized peptide.

The present study develops a rapid, simple and efficient method for the determination of type IV collagenase by using a specific peptide-modified quartz crystal microbalance (QCM). A small peptide (P1), contains a specific sequence (Pro-Gly) and a terminal cysteine, was synthetized and immobilized to the surface of QCM electrode via the reaction between Au and thiol of the cysteine. The peptide bond between proline and glycine can be specific hydrolyzed cleavage by type IV collagenase, which enabled the modified electrode with a high selectivity toward type IV collagenase.

A novel signal-on photoelectrochemical immunosensor for detection of alpha-fetoprotein by in situ releasing electron donor.

A signal-on photoelectrochemical (PEC) immunosensor was constructed for detecting tumor marker in this work. α-fetoprotein (AFP) was chosen as a model analyte to investigate the prepared procedure and the analytical performance of the exploited sensor. In order to construct the sensor, CdSe QDs were used as photoactive material, biotin conjugated AFP antibody (Bio-anti-AFP) as detecting probe, streptavidin (SA) as signal capturing unit, biotin functionalized apoferritin encapsulated ascorbic acid (Bio-APOAA) as amplification unit, which were assembled onto the electrodes.

Nano-encapsulant of ascorbic acid-loaded apoferritin-assisted photoelectrochemical sensor for protease detection.

A signal-on photoelectrochemical (PEC) biosensor based on nano-encapsulant of ascorbic acid-loaded apoferritin-assisted for protease detection is described. The loaded ascorbic acid could be released from the central cavity of apoferritin into the buffer solution as sacrificial electron donor to capture the photo-generated holes of CdTe quantum dots when light is turned on. In this system, the biosensor relied on monitoring the photocurrent intensity as a result of enzymatic substrate proteolysis in the homogeneous aqueous solution.

A Novel Photoelectrochemical Biosensor for Tyrosinase and Thrombin Detection.

A novel photoelectrochemical biosensor for step-by-step assay of tyrosinase and thrombin was fabricated based on the specific interactions between the designed peptide and the target enzymes. A peptide chain with a special sequence which contains a positively charged lysine-labeled terminal, tyrosine at the other end and a cleavage site recognized by thrombin between them was designed. The designed peptide can be fixed on surface of the CdTe quantum dots (QDs)-modified indium-tin oxide (ITO) electrode through electrostatic attraction to construct the photoelectrochemical biosensor.

Label-free detection of pathogenic bacteria via immobilized antimicrobial peptides.

A novel label-free strategy for the detection of bacteria was developed by using a specific antimicrobial peptide (AMP)-functionalized quartz crystal microbalance (QCM) electrode. This electrode interface was successfully applied to detect pathogenic Escherichia coli O157:H7 based on the specific affinity between the small synthetic antimicrobial peptide and the bacterial cell of pathogenic E. coli O157:H7.

Direct electrochemistry of hemoglobin at a graphene gold nanoparticle composite film for nitric oxide biosensing.

A simple two-step method was employed for preparing nano-sized gold nanoparticles-graphene composite to construct a GNPs-GR-SDS modified electrode. Hemoglobin (Hb) was successfully immobilized on the surface of a basal plane graphite (BPG) electrode through a simple dropping technique. Direct electrochemistry and electrocatalysis of the hemoglobin-modified electrode was investigated.

A theophylline quartz crystal microbalance biosensor based on recognition of RNA aptamer and amplification of signal.

A quartz crystal microbalance (QCM) biosensor for theophylline was developed by recognition of RNA aptamer and gold nanoparticle amplification technique. Firstly, a designed small single-stranded RNA, RNA1, was immobilized onto the QCM electrode through a thiol linker. Then, the complementary stranded RNA2, which can combine with RNA1 to form a double-stranded RNA with a recognition unit of theophylline, could be self-assembled on the QCM electrode surface through a hybrid reaction in the presence of theophylline.

Quartz crystal microbalance aptasensor for sensitive detection of mercury(II) based on signal amplification with gold nanoparticles.

We show that a short mercury-specific aptamer (MSA) along with gold nanoparticles (Au-NPs) can be used to determine Hg(II) ion by a combination of a QCM-based sensor and a flow system. The MSA binds specifically to Hg(II), and the Au-NPs can amplify the signal to enhance sensitivity. Specifically, the short thiolated MSAs are immobilized on the surface of the QCM as the capture probe, and the MSAs are linked to the Au-NPs as the linking probe.

Potential-modulated DNA cleavage by (N-salicylideneglycinato)copper(II) complex.

The interaction of aqua (N-salicylideneglycinato)copper(II) (Cu(salgly)2+) complex with calf thymus DNA has been investigated by cyclic voltammetry. Potential-modulated DNA cleavage in the presence of Cu(salgly)2+ complex was performed at a gold electrode in a thin layer cell. DNA can be efficiently cleaved by electrochemically reducing Cu(salgly)2+ complex to Cu(salgly)+ complex at -0.

A reagentless biosensor of nitric oxide based on direct electron transfer process of cytochrome c on multi-walled carbon nanotube.

Direct electron transfer between Cytochrome c (Cyt.c) and electrode can be achieved through immobilizing Cyt.c on the surface of multi-walled carbon nanotubes (MWNTs).