The insurmountable charge transfer impedance at the Li metal/solid polymer electrolytes(SPEs)interface at room temperature as well as the ascending risk of short circuits at the operating temperature higher than the m...The insurmountable charge transfer impedance at the Li metal/solid polymer electrolytes(SPEs)interface at room temperature as well as the ascending risk of short circuits at the operating temperature higher than the melting point,dominantly limits their applications in solid-state batteries(SSBs).Although the inorganic filler such as CeO_(2)nanoparticle content of composite solid polymer electrolytes(CSPEs)can significantly reduce the enormous charge transfer impedance at the Li metal/SPEs interface,we found that the required content of CeO_(2)nanoparticles in SPEs varies for achieving a decent interfacial charge transfer impedance and the bulk ionic conductivity in CSPEs.In this regard,a sandwich-type composited solid polymer electrolyte with a 10%CeO_(2)CSPEs interlayer sandwiched between two 50%CeO_(2)CSPEs thin layers(sandwiched CSPEs)is constructed to simultaneously achieve low charge transfer impedance and superior ionic conductivity at 30℃.The sandwiched CSPEs allow for stable cycling of Li plating and stripping for 1000 h with 129 mV polarized voltage at 0.1 mA cm^(-2)and 30℃.In addition,the LiFePO_(4)/Sandwiched CSPEs/Li cell also exhibits exceptional cycle performance at 30℃and even elevated120℃without short circuits.Constructing multi-layered CSPEs with optimized contents of the inorganic fillers can be an efficient method for developing all solid-state PEO-based batteries with high performance at a wide range of temperatures.展开更多
In this work,in order to obtain deep clean gas oil,a novel organic–inorganic hybrid(n-C4H9)4N)7H5Si2W18Cd4O68@β-cyclodextrin(abbreviated as TBA-Si WCd@β-CD)composite was synthesized by supporting quaternary ammoniu...In this work,in order to obtain deep clean gas oil,a novel organic–inorganic hybrid(n-C4H9)4N)7H5Si2W18Cd4O68@β-cyclodextrin(abbreviated as TBA-Si WCd@β-CD)composite was synthesized by supporting quaternary ammonium salt of sandwich-type polysilicotungstate onβ-cyclodextrin(TBA-SiWCd@β-CD)as an efficient catalyst for oxidative desulfurization(ODS)of gas oil.The successful composition of the materials explained by the formation of host–guest inclusion complex,which confirmed through FTIR,UV–vis,XRD,SEM,and EDX characterization analyses.Experimental results revealed that the levels of sulfur content and mercaptan compounds of gas oil lowered with 97%removal efficiency.Compared with the ODS treatment of gas oil,the TBA-Si WCd@β-CD composite showed an outstanding catalytic performance for the oxidation of dibenzothiophene(DBT)in the prepared model fuel.The main factors that influence the desulfurization efficiency and the kinetic study of the ODS process were investigated.The prepared heterogeneous catalyst was found to give remarkable reusability for five runs without a discernible decrease in its activity.This study suggested the potential application of the TBA-Si WCd@β-CD catalyst for removal of hazardous sulfur compounds from gas oil fuel.展开更多
A new organic-inorganic hybrid sandwich-type arsenotungstate[H2dap]2H2[Ni（dap）2] [Ni（dap）2（H2O）2][Ni4（H2O）2（B-α-AsVW9O34）2]·8H2O 1 （dap = 1,2-diaminopropane） has been synthesized by the reaction of N...A new organic-inorganic hybrid sandwich-type arsenotungstate[H2dap]2H2[Ni（dap）2] [Ni（dap）2（H2O）2][Ni4（H2O）2（B-α-AsVW9O34）2]·8H2O 1 （dap = 1,2-diaminopropane） has been synthesized by the reaction of Na6[AsIII2W21O69（H2O）]·nH2O, NiCl2·6H2O and dap under hydrothermal conditions and structurally characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis and single-crystal X-ray diffraction. 1 crystallizes in the monoclinic space group P21/n with a = 13.5133（19）, b = 19.043（3）, c = 17.647（2）, β = 102.585（2）°, V = 4432.0（11） 3, T = 296（2） K, Z = 2, μ = 25.350 mm–1, GOOF = 1.058, R = 0.0353 and wR = 0.0838. The molecular unit of 1 consists of two diprotonated [H2dap]2＋ cations, two protons, one four-coordinate [Ni（dap）2]2＋ cation, one six-coordinate [Ni（dap）2（H2O）2]2＋ cation, one classic tetra-NiII substituted sandwich-type [Ni4（H2O）2（B-α-AsVW9O34）2]10– polyoxoanion and eight lattice water molecules. Furthermore, some reported different types of transition-metal substituted sandwich-type polyoxoanions are summarized and compared.展开更多
The title compound {[Cu（abpy）2]（H3bptc）·（H2O）}n, an ion-pair complex of [Cu（abpy）2]＋ with [（H3bptc）]- （abpy = 3,3＇-dimethyl-2,2＇-bipyridine and H4bptc = 1,1＇-biphenyl-2,2＇,3,3＇-tetracarboxylic a...The title compound {[Cu（abpy）2]（H3bptc）·（H2O）}n, an ion-pair complex of [Cu（abpy）2]＋ with [（H3bptc）]- （abpy = 3,3＇-dimethyl-2,2＇-bipyridine and H4bptc = 1,1＇-biphenyl-2,2＇,3,3＇-tetracarboxylic acid）, has been synthesized by a hydrothermal reaction, and its structure was deter- mined by X-ray diffraction and characterized by elemental analysis and IR spectrum. The crystal is of triclinic, space group P1 with a = 8.4955（12）, b = 15.164（2）, c = 15.303（2）, α = 105.704（3）, β = 97.374（3）, γ = 96.764（3）o, CuC40H35N4O9, Mr = 779.26, V = 1857.9（4）3, Dc = 1.393 g/cm3, F（000） = 808, μ = 0.649 mm-1, S = 1.026 and Z = 2. The final R = 0.0493 and wR = 0.1034 for 4026 observed reflections with I 2σ（I）. The copper（I） coordination polymer demonstrates a 3-D sandwich-type structure containing 2-D double H3bptc-chain layers intercalated with the [Cu（abpy）2]＋ layers by extensive hydrogen bonding interactions.展开更多
The purpose of this article is to obtain some subordination and superordi- nation preserving properties of meromorphic multivalent functions in the punctured open unit disk associated with the Liu-Srivastava operator....The purpose of this article is to obtain some subordination and superordi- nation preserving properties of meromorphic multivalent functions in the punctured open unit disk associated with the Liu-Srivastava operator. The sandwich-type results for these meromorphic multivalent functions are also considered.展开更多
The crystal structure of the title compound, [enH2][Fe{MoⅤ6O12(OH)3(HPO4)- (H2PO4)3}2]6en6H2O (en = H2NCH2CH2NH2), hydrothermally synthesized from a mixture of Na2MoO42H2O, Fe2(SO4)3, H3PO4, H2N(CH2)2NH2 and water, h...The crystal structure of the title compound, [enH2][Fe{MoⅤ6O12(OH)3(HPO4)- (H2PO4)3}2]6en6H2O (en = H2NCH2CH2NH2), hydrothermally synthesized from a mixture of Na2MoO42H2O, Fe2(SO4)3, H3PO4, H2N(CH2)2NH2 and water, has been determined by single- crystal X-ray diffraction. The crystal is of triclinic, space group P?with a = 11.9014(1), b = 13.4246(2), c = 13.8719(2) , a = 87.465(1), b = 69.981(1), g = 64.960(1)? V = 1873.46(4) 3, Z = 1, Mr = 2997.89, F(000) = 1466, m = 2.427 mm-1 and Dc = 2.657 g/cm3. The final R = 0.0404 for 5570 observed reflections (I > 2s(I)). The structural analysis reveals that each cluster anion contains two coplanar {Mo6} rings of six edge-sharing Mo(O5OH) octahedra, and the two {Mo6} rings are linked together through one octahedral FeⅡ ion to generate a sandwich-type cluster with rigorous () symmetry. Moreover, these clusters are further linked into a three-dimensional frame- work by hydrogen bonds.展开更多
A novel poly（N-isopropylacrylamide）-based sandwich-typed hydrogel, which was featured with both ends of linear poly（N-isopropylaerylamide） （PNIPAM） chains being grafted onto cross-linked PNIPAM chains, was succe...A novel poly（N-isopropylacrylamide）-based sandwich-typed hydrogel, which was featured with both ends of linear poly（N-isopropylaerylamide） （PNIPAM） chains being grafted onto cross-linked PNIPAM chains, was successfully prepared in a three-step process by a method of sequential synthesis. The proposed hydrogel displays faster and hydration/dehydration dynamic response to temperature cycling owing to linear PNIPAM chains to form big-pore structure. This work may lead to high attraction for targeting drug delivery systems, polymeric pump, sensors and so on.展开更多
A novel thermo-responsive hydrogel column, featured with both ends of linear poly（N- isopropylacrylarnide） （PNIPAM） chains being grafted onto cross-linked PNIPAM chains, was reported. The laterally sandwich-typed ...A novel thermo-responsive hydrogel column, featured with both ends of linear poly（N- isopropylacrylarnide） （PNIPAM） chains being grafted onto cross-linked PNIPAM chains, was reported. The laterally sandwich-typed hydrogel columns were fabricated by radical polymerization in a three-step process using a method of ice-melting synthesis. The initiating path, morphology and thermoresponsive characteristics of the prepared hydrogel columns were experimentally studied. The results show that the hydrogel column obtained by the initiator inside part has more quick swelling and deswelling rates responsing to temperature cycling than other hydrogels owing to linear PNIPAM chains to form supermacroporous structure. The proposed hydrogel structure provide a new mode of the phase transition behavior for thermo-sensitive ＂smart＂ or ＂intelligent＂ monodisperse micro-actuators, which is highly attractive for targeting drug delivery systems, chemical separations, and sensors and so on.展开更多
It is a challenge to reduce the dielectric loss and increase the tunability of pure barium strontium titanate(BST)films for microwave tunable application because these two properties change simultaneously.Herein,a nov...It is a challenge to reduce the dielectric loss and increase the tunability of pure barium strontium titanate(BST)films for microwave tunable application because these two properties change simultaneously.Herein,a novel composite of strontium titanate(ST)and potassium-doped BST(KBST)has been designed as ST/KBST/ST sandwich-type film with various ST and KBST layers.X-ray diffraction patterns show that the film exhibits cubic perovskite polycrystalline structure composed of BST and ST phase,mainly grow along(110)crystal plane with average grain size of less than 20 nm and decreasing BST phase/ST phase ratio with increasing film thickness.Scanning electron microscope shows that no interfacial layer can be observed,indicating that ST and KBST are fully compounded.Low dielectric loss and high tunability at-10-10 V and stable and excellent dielectric properties at 1 GHz are achieved,meeting the needs of microwave tunable application at high frequency.The surface structures are also studied by other analysis methods,and ST/MgBST/ST sandwich-type film is compared.展开更多
The sandwich-type lateral fl ow assays relying on dual aptamers with high sensitivity and specifi city have been broadly explored.However,it is unlikely to match a pair of specifi c aptamers that can bind a small mole...The sandwich-type lateral fl ow assays relying on dual aptamers with high sensitivity and specifi city have been broadly explored.However,it is unlikely to match a pair of specifi c aptamers that can bind a small molecular target(e.g.,cocaine)simultaneously due to the steric hindrance.In response,we herein introduced the strategy of“one divides into two”into the construction of sandwich-type lateral fl ow strip assay(LFSA).Specifi cally,we split a single cocaine-recognizing aptamer into two segments,either of which was conjugated with gold nanoparticles(AuNPs)or labeled with biotin,serving as signal probe and capture probe,respectively.Upon the presence of the target molecule,a ternary sandwich complex comprised of the two halves of the aptamer and the target formed.Such sandwich-type LFSA exhibited an excellent nonlinear logarithmic response in the range from 10μmol/L to 5 mmol/L with R^(2)=0.9994.The sensitive on-site detection of cocaine in artifi cial biological samples including urine and sweat was achieved within 15 min,with the visual limit of detection as low as 50μmol/L for urine and 200μmol/L for sweat,and the recovery rates of 83.6-107.4%.展开更多
The electronic behavior of sandwich-type rare earth octaethylporphyrinates Ln(oep)2 and Ln2(oep)3 (Ln=Ce, Pr and Eu) was characterized by measurements of the UV-vis or near infrared spectra and D.C. conductivity. Howe...The electronic behavior of sandwich-type rare earth octaethylporphyrinates Ln(oep)2 and Ln2(oep)3 (Ln=Ce, Pr and Eu) was characterized by measurements of the UV-vis or near infrared spectra and D.C. conductivity. However, the conductivity values measured at room temperature were distributed in an order of 10-7 to 10-8 S.cm-1 even after the partial oxidation of complex with the complexes with iodine and no remarkable change was observed among the complexes such as LnIV(Por2-)2 (Ln=Ce) and LnIV(Por2-)(Por.-) (Ln=Ce) or Ln2III(Por2-)3 and LnIII2(Por2-)2(Por-).展开更多
In recent years,sandwich-type rare earth tetrapyrrole derivatives,have attracted more and more attention as material for conductimetric sensors.They have not only great chemical stability and processability,but also f...In recent years,sandwich-type rare earth tetrapyrrole derivatives,have attracted more and more attention as material for conductimetric sensors.They have not only great chemical stability and processability,but also flexible molecular structure,which is a key to adjustable semiconductor properties.In this mini review,we focus mainly on the development of tetrapyrrolato-rare earth sandwich-type complexes as the semiconducting active layer in the gas sensors published in the last ten years(2010-2020).The main part includes two sections.In the single component gas sensing of sandwich rare earth tetrapyrrole complexes,we describe the influence factors of the single-component semiconducting active layer on the sensing performance of tetrapyrrolato-rare earth sandwich-type complexes,including substituents,central metals and π-conjugate systems.In the multi-component gas sensors,the synergistic effect between tetrapyrrolato-rare earth sandwich-type complex and other materials on improving sensitivity and conductivity has been discussed briefly.展开更多
基金supported by the National Key R&D Program of China(2021YFB2400400)the National Natural Science Foundation of China(Grant No.22379120,22179085)+5 种基金the Key Research and Development Plan of Shanxi Province(China,Grant No.2018ZDXM-GY-135,2021JLM-36)the National Natural Science Foundation of China(Grant No.22108218)the“Young Talent Support Plan”of Xi’an Jiaotong University(71211201010723)the Qinchuangyuan Innovative Talent Project(QCYRCXM-2022-137)the“Young Talent Support Plan”of Xi’an Jiaotong University(HG6J003)the“1000-Plan program”of Shaanxi Province。
文摘The insurmountable charge transfer impedance at the Li metal/solid polymer electrolytes(SPEs)interface at room temperature as well as the ascending risk of short circuits at the operating temperature higher than the melting point,dominantly limits their applications in solid-state batteries(SSBs).Although the inorganic filler such as CeO_(2)nanoparticle content of composite solid polymer electrolytes(CSPEs)can significantly reduce the enormous charge transfer impedance at the Li metal/SPEs interface,we found that the required content of CeO_(2)nanoparticles in SPEs varies for achieving a decent interfacial charge transfer impedance and the bulk ionic conductivity in CSPEs.In this regard,a sandwich-type composited solid polymer electrolyte with a 10%CeO_(2)CSPEs interlayer sandwiched between two 50%CeO_(2)CSPEs thin layers(sandwiched CSPEs)is constructed to simultaneously achieve low charge transfer impedance and superior ionic conductivity at 30℃.The sandwiched CSPEs allow for stable cycling of Li plating and stripping for 1000 h with 129 mV polarized voltage at 0.1 mA cm^(-2)and 30℃.In addition,the LiFePO_(4)/Sandwiched CSPEs/Li cell also exhibits exceptional cycle performance at 30℃and even elevated120℃without short circuits.Constructing multi-layered CSPEs with optimized contents of the inorganic fillers can be an efficient method for developing all solid-state PEO-based batteries with high performance at a wide range of temperatures.
文摘In this work,in order to obtain deep clean gas oil,a novel organic–inorganic hybrid(n-C4H9)4N)7H5Si2W18Cd4O68@β-cyclodextrin(abbreviated as TBA-Si WCd@β-CD)composite was synthesized by supporting quaternary ammonium salt of sandwich-type polysilicotungstate onβ-cyclodextrin(TBA-SiWCd@β-CD)as an efficient catalyst for oxidative desulfurization(ODS)of gas oil.The successful composition of the materials explained by the formation of host–guest inclusion complex,which confirmed through FTIR,UV–vis,XRD,SEM,and EDX characterization analyses.Experimental results revealed that the levels of sulfur content and mercaptan compounds of gas oil lowered with 97%removal efficiency.Compared with the ODS treatment of gas oil,the TBA-Si WCd@β-CD composite showed an outstanding catalytic performance for the oxidation of dibenzothiophene(DBT)in the prepared model fuel.The main factors that influence the desulfurization efficiency and the kinetic study of the ODS process were investigated.The prepared heterogeneous catalyst was found to give remarkable reusability for five runs without a discernible decrease in its activity.This study suggested the potential application of the TBA-Si WCd@β-CD catalyst for removal of hazardous sulfur compounds from gas oil fuel.
基金supported by the Natural Science Foundation of Henan Province (No. 092300410119)the Natural Science Foundation of Henan University (No. 2008YBZR010)
文摘A new organic-inorganic hybrid sandwich-type arsenotungstate[H2dap]2H2[Ni（dap）2] [Ni（dap）2（H2O）2][Ni4（H2O）2（B-α-AsVW9O34）2]·8H2O 1 （dap = 1,2-diaminopropane） has been synthesized by the reaction of Na6[AsIII2W21O69（H2O）]·nH2O, NiCl2·6H2O and dap under hydrothermal conditions and structurally characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis and single-crystal X-ray diffraction. 1 crystallizes in the monoclinic space group P21/n with a = 13.5133（19）, b = 19.043（3）, c = 17.647（2）, β = 102.585（2）°, V = 4432.0（11） 3, T = 296（2） K, Z = 2, μ = 25.350 mm–1, GOOF = 1.058, R = 0.0353 and wR = 0.0838. The molecular unit of 1 consists of two diprotonated [H2dap]2＋ cations, two protons, one four-coordinate [Ni（dap）2]2＋ cation, one six-coordinate [Ni（dap）2（H2O）2]2＋ cation, one classic tetra-NiII substituted sandwich-type [Ni4（H2O）2（B-α-AsVW9O34）2]10– polyoxoanion and eight lattice water molecules. Furthermore, some reported different types of transition-metal substituted sandwich-type polyoxoanions are summarized and compared.
基金supported by the National Natural Science Foundation of China (No. 10947162)the Natural Science Foundation of Henan Province (No. 2010A140009)the International Technology Cooperation Project of Science and Technology Department of Henan Province (No. 104300510044)
文摘The title compound {[Cu（abpy）2]（H3bptc）·（H2O）}n, an ion-pair complex of [Cu（abpy）2]＋ with [（H3bptc）]- （abpy = 3,3＇-dimethyl-2,2＇-bipyridine and H4bptc = 1,1＇-biphenyl-2,2＇,3,3＇-tetracarboxylic acid）, has been synthesized by a hydrothermal reaction, and its structure was deter- mined by X-ray diffraction and characterized by elemental analysis and IR spectrum. The crystal is of triclinic, space group P1 with a = 8.4955（12）, b = 15.164（2）, c = 15.303（2）, α = 105.704（3）, β = 97.374（3）, γ = 96.764（3）o, CuC40H35N4O9, Mr = 779.26, V = 1857.9（4）3, Dc = 1.393 g/cm3, F（000） = 808, μ = 0.649 mm-1, S = 1.026 and Z = 2. The final R = 0.0493 and wR = 0.1034 for 4026 observed reflections with I 2σ（I）. The copper（I） coordination polymer demonstrates a 3-D sandwich-type structure containing 2-D double H3bptc-chain layers intercalated with the [Cu（abpy）2]＋ layers by extensive hydrogen bonding interactions.
基金supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education,Science and Technology (2010-0017111)
文摘The purpose of this article is to obtain some subordination and superordi- nation preserving properties of meromorphic multivalent functions in the punctured open unit disk associated with the Liu-Srivastava operator. The sandwich-type results for these meromorphic multivalent functions are also considered.
基金This work was supported by the State Key Laboratory of Structural Chemistry (030065) the Chinese Academy of Sciences the NNSFC (20073048) and the NSF of Fujian province (2002F015)
文摘The crystal structure of the title compound, [enH2][Fe{MoⅤ6O12(OH)3(HPO4)- (H2PO4)3}2]6en6H2O (en = H2NCH2CH2NH2), hydrothermally synthesized from a mixture of Na2MoO42H2O, Fe2(SO4)3, H3PO4, H2N(CH2)2NH2 and water, has been determined by single- crystal X-ray diffraction. The crystal is of triclinic, space group P?with a = 11.9014(1), b = 13.4246(2), c = 13.8719(2) , a = 87.465(1), b = 69.981(1), g = 64.960(1)? V = 1873.46(4) 3, Z = 1, Mr = 2997.89, F(000) = 1466, m = 2.427 mm-1 and Dc = 2.657 g/cm3. The final R = 0.0404 for 5570 observed reflections (I > 2s(I)). The structural analysis reveals that each cluster anion contains two coplanar {Mo6} rings of six edge-sharing Mo(O5OH) octahedra, and the two {Mo6} rings are linked together through one octahedral FeⅡ ion to generate a sandwich-type cluster with rigorous () symmetry. Moreover, these clusters are further linked into a three-dimensional frame- work by hydrogen bonds.
基金Funded by the National Natural Science Foundation of China (20976202)the Natural Science Foundation of Hubei Province (2009CDB161)
文摘A novel poly（N-isopropylacrylamide）-based sandwich-typed hydrogel, which was featured with both ends of linear poly（N-isopropylaerylamide） （PNIPAM） chains being grafted onto cross-linked PNIPAM chains, was successfully prepared in a three-step process by a method of sequential synthesis. The proposed hydrogel displays faster and hydration/dehydration dynamic response to temperature cycling owing to linear PNIPAM chains to form big-pore structure. This work may lead to high attraction for targeting drug delivery systems, polymeric pump, sensors and so on.
基金the National Natural Science Foundation of China (No.20976202)the Natural Science Foundation of Hubei Province (No.2009CDB161)
文摘A novel thermo-responsive hydrogel column, featured with both ends of linear poly（N- isopropylacrylarnide） （PNIPAM） chains being grafted onto cross-linked PNIPAM chains, was reported. The laterally sandwich-typed hydrogel columns were fabricated by radical polymerization in a three-step process using a method of ice-melting synthesis. The initiating path, morphology and thermoresponsive characteristics of the prepared hydrogel columns were experimentally studied. The results show that the hydrogel column obtained by the initiator inside part has more quick swelling and deswelling rates responsing to temperature cycling than other hydrogels owing to linear PNIPAM chains to form supermacroporous structure. The proposed hydrogel structure provide a new mode of the phase transition behavior for thermo-sensitive ＂smart＂ or ＂intelligent＂ monodisperse micro-actuators, which is highly attractive for targeting drug delivery systems, chemical separations, and sensors and so on.
基金financially supported by the Key Project of National Natural Science Foundation of China(No.11832007)the Applied Basic Research Program of Sichuan(No.19YYJC1846)the Science and Technology Achievement Transfer and Transformation of Sichuan(No.20ZHSF0154)。
文摘It is a challenge to reduce the dielectric loss and increase the tunability of pure barium strontium titanate(BST)films for microwave tunable application because these two properties change simultaneously.Herein,a novel composite of strontium titanate(ST)and potassium-doped BST(KBST)has been designed as ST/KBST/ST sandwich-type film with various ST and KBST layers.X-ray diffraction patterns show that the film exhibits cubic perovskite polycrystalline structure composed of BST and ST phase,mainly grow along(110)crystal plane with average grain size of less than 20 nm and decreasing BST phase/ST phase ratio with increasing film thickness.Scanning electron microscope shows that no interfacial layer can be observed,indicating that ST and KBST are fully compounded.Low dielectric loss and high tunability at-10-10 V and stable and excellent dielectric properties at 1 GHz are achieved,meeting the needs of microwave tunable application at high frequency.The surface structures are also studied by other analysis methods,and ST/MgBST/ST sandwich-type film is compared.
基金supported by the National Natural Science Foundation of China(22090050,22122410,21874121)the National Key Research and Development Program of China(2018YFE0206900)+1 种基金Hubei Provincial Natural Science Foundation of China(2020CFA037)Zhejiang Provincial Natural Science Foundation of China(LD21B050001)
文摘The sandwich-type lateral fl ow assays relying on dual aptamers with high sensitivity and specifi city have been broadly explored.However,it is unlikely to match a pair of specifi c aptamers that can bind a small molecular target(e.g.,cocaine)simultaneously due to the steric hindrance.In response,we herein introduced the strategy of“one divides into two”into the construction of sandwich-type lateral fl ow strip assay(LFSA).Specifi cally,we split a single cocaine-recognizing aptamer into two segments,either of which was conjugated with gold nanoparticles(AuNPs)or labeled with biotin,serving as signal probe and capture probe,respectively.Upon the presence of the target molecule,a ternary sandwich complex comprised of the two halves of the aptamer and the target formed.Such sandwich-type LFSA exhibited an excellent nonlinear logarithmic response in the range from 10μmol/L to 5 mmol/L with R^(2)=0.9994.The sensitive on-site detection of cocaine in artifi cial biological samples including urine and sweat was achieved within 15 min,with the visual limit of detection as low as 50μmol/L for urine and 200μmol/L for sweat,and the recovery rates of 83.6-107.4%.
文摘The electronic behavior of sandwich-type rare earth octaethylporphyrinates Ln(oep)2 and Ln2(oep)3 (Ln=Ce, Pr and Eu) was characterized by measurements of the UV-vis or near infrared spectra and D.C. conductivity. However, the conductivity values measured at room temperature were distributed in an order of 10-7 to 10-8 S.cm-1 even after the partial oxidation of complex with the complexes with iodine and no remarkable change was observed among the complexes such as LnIV(Por2-)2 (Ln=Ce) and LnIV(Por2-)(Por.-) (Ln=Ce) or Ln2III(Por2-)3 and LnIII2(Por2-)2(Por-).
基金the National Natural Science Foundation of China(21771192)。
文摘In recent years,sandwich-type rare earth tetrapyrrole derivatives,have attracted more and more attention as material for conductimetric sensors.They have not only great chemical stability and processability,but also flexible molecular structure,which is a key to adjustable semiconductor properties.In this mini review,we focus mainly on the development of tetrapyrrolato-rare earth sandwich-type complexes as the semiconducting active layer in the gas sensors published in the last ten years(2010-2020).The main part includes two sections.In the single component gas sensing of sandwich rare earth tetrapyrrole complexes,we describe the influence factors of the single-component semiconducting active layer on the sensing performance of tetrapyrrolato-rare earth sandwich-type complexes,including substituents,central metals and π-conjugate systems.In the multi-component gas sensors,the synergistic effect between tetrapyrrolato-rare earth sandwich-type complex and other materials on improving sensitivity and conductivity has been discussed briefly.
