查看更多>>摘要：Fast Fe(Ⅲ)/Fe(Ⅱ)circulation in heterogeneous peroxymonosulfate(PMS)activation remains as a bottle-neck issue that restricts the development of PMS based advanced oxidation processes.Herein,we pro-posed a facile ammonia reduction strategy and synthesized a novel FeVO3-x catalysts to activate PMS for the degradation of a typical pharmaceutical,carbamazepine(CBZ).Rapid CBZ removal could be achieved within 10 min,which outperforms most of the other iron or vanadium-based catalysts.Electron para-magnetic resonance analysis and chemical probe experiments revealed SO4·-,·OH,O2·-and high valent iron(Fe(Ⅳ))were all generated in this system,but SO4·-and Fe(Ⅳ)primarily contributed to the degrada-tion of CBZ.Besides,X-ray photoelectron spectroscopy and X-ray adsorption spectroscopy indicated that both the generated low-valent V provides and oxygen vacancy acted as superior electron donors and ac-celerated internal electron transfer via the unsaturated V-O-Fe bond.Finally,the proposed system also exhibited satisfactory performance in practical applications.This work provides a promising platform in heterogeneous PMS activation.
查看更多>>摘要：As a new concept having emerged in last few years,the"deep eutectic solvents"(DESs)effect inte-grated into the imprinting technology inevitably exposes design limitations of stimuli-responsive molec-ularly imprinted polymers(MIPs),as well as inadequate analysis of the adsorption performance of MIPs.Herein,a simple yet defined N-isopropylacrylamide/(3-acrylamidopropyl)trimethylammonium chloride(NIPAM/APTMAC)binary DESs system was proposed to prepare intelligent MIPs with thermo-sensitivity.Accordingly,magnetic and thermo-responsive MIPs based on functional monomers-derived DESs(TM-DESs-MIPs1)were synthesized,revealing DESs effect-regulated affinity/kinetics for the enhanced adsorp-tion capability,eco-friendly thermo-regulated elution for high release efficiency,and simple magnetic separation,along with superior selectivity to rhein(RH)and good regeneration ability.TM-DESs-MIPs1 were utilized to extract RH from Cassiae semen samples coupled with high performance liquid chro-matography(HPLC),yielding satisfactory recoveries(79.47％-110.82％)and low limits of detection(LOD)(16.67 μg/L).Another two kinds of MIPs adopting the thermo-responsive moiety-derived DESs effect strat-egy further demonstrated great applicability of such intelligent MIPs for analyses of complicated samples.
查看更多>>摘要：Paper-based biosensors are widely employed in point-of-care testing(POCT)due to their convenience,portability,low cost,and ease of use.This study reports an integrated distance-based paper biosensor fabricated with a mesoporous membrane coated with stimuli-responsive polymer.The detection of α-amylase(AMY)using amylopectin-coated mesoporous membrane is demonstrated as an example.After introducing the AMY solution,it is observed that the aqueous solution flows along the paper strip due to AMY-catalyzed hydrolysis of amylopectin.The flow distance is proportional to the concentration of AMY with a detection limit as low as 4 mU/mL.In addition,the detection of AMY is demonstrated in human serum.Furthermore,the inhibitory effect of acarbose on AMY is evaluated.This reagent-free and dispos-able biosensor allows single-step rapid detection of the analyte.This approach is very promising for the development of user-friendly,equipment-free,and cost-effective biosensors with remarkable sensitivity and excellent selectivity for disease diagnosis and hypoglycemic drug screening.
Ebtihaj Mohammed SullamKhalid Mohammed AdamJuanjuan LiuHongli Chen...
451-455页
查看更多>>摘要：Fluorescent silicon quantum dots(Si QDs)were hydrothermally synthesized from a mixture of 3(2-aminoethylamino)propyl(dimethoxymethylsilane)(AEAPDMMS)and poly(vinylpyrrolidine)(PVP).The resulting Si QDs exhibited good water solubility and high stability.Under the optimized conditions,the probe revealed an excellent linear fluorescence quenching effect on Co2+ranging from 1 μmol/L to 120μmol/L with a limit of detection of 0.37 μmol/L(based on 3s/k).The quenching mechanism was stud-ied,showing that static quenching(SQE)causes the main effect.Furthermore,the test paper based on Si QDs was prepared,which is cost-effective,high sensitivity,good selectivity,easy to use and show excel-lent anti-interference capability.This method was applied to analyze the content of Co2+in environmen-tal water samples with satisfying results.
查看更多>>摘要：Droplet manipulation on an open surface has great potential in chemical analysis and biomedicine engi-neering.However,most of the reported platforms designed for the manipulation of water droplets cannot thoroughly solve the problem of droplet evaporation.Herein,we report a shape-reconfigurable micropil-lar array chip for the manipulation of water droplets,oil droplets and water-in-oil droplets.Water-in-oil droplets provide an enclosed space for water droplets,preventing the evaporation in an open environ-ment.Perfluoropolyether coated on the surface of the chip effectively reduces the droplet movement resistance.The micropillar array chip has light and magnetic dual-response due to the Fe3O4 nanoparti-cles and the reduced iron powder mixed in the shape-memory polymer.The micropillars irradiated by a near-infrared laser bend under the magnetic force,while the unirradiated micropillars still keep their original shape.In the absence of a magnetic field,when the micropillars in a temporary shape are irradi-ated by the near-infrared laser to the transition temperature,the micropillars return to their initial shape.In this process,the surface morphology gradient caused by the deformation of the micropillars and the surface tension gradient caused by the temperature change jointly produce the driving force of droplet movement.
查看更多>>摘要：Alcohol consumption is one of the leading causes of death worldwide.Adolescence is a critical period of structural and functional maturation of the brain.Adolescent alcohol use can alter epigenetic modifica-tions.However,little is known on the long-term effects of alcohol consumption during adolescence on RNA epigenetic modifications in brain.Herein,we systematically explored the long-term effects of alco-hol exposure during adolescence on small RNA modifications in adult rat brain tissues by comprehensive liquid chromatography-electrospray ionization-tandem mass spectrometry(LC-ESI-MS/MS)analysis.We totally detected 26 modifications in small RNA of brain tissues.Notably,we observed most of these mod-ifications were decreased in brain tissues.These results suggest that alcohol exposure during adolescence may impose a long-lasting impact on RNA modifications in brain tissues.This is the first report that alco-hol use during adolescence can alter RNA modifications in adult brain.Collectively,this study suggests a long-term adverse effects of alcohol consumption on brain from RNA epigenetics angle by comprehensive mass spectrometry analysis.
查看更多>>摘要：DNA circuits are powerful tools in various applications such as logical computation,molecular diagnosis and synthetic biology.Leakage is a major problem in constructing complex DNA circuits.It directly af-fects the output signal and harms the circuit's performance significantly.In the traditional DNA circuits,the gate complex is a duplex structure.There are insufficient energy barriers to prevent spontaneous de-tachment of strands,resulting in a leak prone.Herein,we have developed triplex-structure based DNA circuit with ultra-low leakage and high signal-to-noise ratio(SNR).The triplex structure improves the stability in the absence of input.At the same time,the driving force of the strand displacement cascades reduces the influence of the triplex structure on the desired reaction.The SNR of the DNA circuit was increased to 695,while the desired reaction rate remained 90％of the conventional translator circuit.The triplex-structure mediated leakage prevention strategy was further tested at different temperatures and in DNA translator and seesaw circuits.We also constructed modular basic logic gates with a high effi-ciency and low leakage.On this basis,we further constructed triplex-structure based tertiary DNA logic circuits,and the SNR reached 295,which,to the best of our knowledge,was among the highest of the field.We believe that our scheme provides a novel,valid,and general tool for reducing leakages,and we anticipate that it will be widely adopted in DNA nanotechnology.
查看更多>>摘要：Immobilizing enzyme to nano interfaces has demonstrated to be a favorable strategy for prompting the industrialized application of enzyme.Despite tremendous endeavor has been devoted to using gold nanoparticles(AuNPs)as conjugation matrix due to its fascinating physico-chemical properties,main-taining enzymatic activity while circumventing cumbersome modification remains a formidable chal-lenge.Herein,the freezing-directed conjugation of enzyme/nano interfaces was constructed without extra reagent.As the proof of concept,glucose oxidase(GOx)was chosen as model enzyme.The one-pot con-jugation process can be facilely completed at-20 ℃ under aqueous solution.Moreover,with the loading of GOx on AuNP at freezing,the enzyme exhibited superior catalytic activity and stability upon ther-mal and pH perturbation.The mechanism of boosted activity was then discussed in detail.It was found that higher loading density under freezing condition and more enzyme tending to bind AuNPs via Au-S bond were the main factors for the superior activity.More importantly,this methodology was universal and can also be applied to other enzyme which contains natural cysteine,such as horseradish peroxi-dase(HRP)and papain.This facile conjugation strategy accompanied by remarkable bioactivity expand the possibilities for enzymatic biosensing,microdevice and even drug delivery.
查看更多>>摘要：Electrosynthesis of hydrogen peroxide(H2O2)is an on-site method that enables independent distribution applications in many fields due to its small-scale and sustainable features.The crucial point remains de-veloping highly active,selective and cost-effective electrocatalysts.The electrosynthesis of H2O2 in acidic media is more practical owing to its stability and no need for further purification.We herein report a phosphorus and selenium tuning Co-based non-precious catalyst(CoPSe)toward two-electron oxygen re-duction reaction(2e-ORR)to produce H2O2 in acidic media.The starting point of using both P and Se is finding a balance between strong ORR activity of CoSe and weak activity of CoP.The results demonstrated that the CoPSe catalyst exhibited the optimized 2e-ORR activity compared with CoP and CoSe.It dis-closed an onset potential of 0.68 V and the H2O2 selectivity 76％-85％in a wide potential range(0-0.5 V).Notably,the CoPSe catalyst overcomes a significant challenge of a narrow-range selectivity for transition-metal based 2e ORR catalysts.Finally,combining with electro-Fenton reaction,an on-site system was constructed for efficient degradation of organic pollutants.This work provides a promising non-precious Co-based electrocatalyst for the electrosynthesis of H2O2 in acidic media.
查看更多>>摘要：Development of new metal-free heterogeneous catalysts has long been the focus of intense research in-terest.The integration of multifunctional monomers into the skeletons of porous organic polymers(POPs)provides an efficient pathway to achieve this goal.Herein,we rationally designed and successfully pre-pared a new Tröger's base(TB)-derived POPs by insertion of pillar[5]arene macrocycle as a positively auxiliary group.Combined the both merits of pillar[5]arene macrocycle and TB moiety,the as-prepared polymer was further explored as an effective metal-free heterogeneous catalyst and exhibited promoted catalytic performance in Knoevenagel condensation and CO2 conversion.This work provides a new strat-egy to fabricate metal-free heterogeneous catalysts based on macrocyclic POPs.
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