查找使用阿拉丁产品的科研文献

A sandwich-configuration ratiometric electrochemical immunosensor based on dual signal amplification of NH2-GO/Fe-Ni@Ti0033C2Tx/NH2-GO/Fc@AuNPs and BPNPs/AuPt-MB for the detection of survivin

Zhiren Zhou,Lina Zou,Ping Zhang,Chunmei Li,Ye Zhu,Huanyu Ren,Zheng Li,Huiru Niu,Hao Liao,Xiaojing Zhang,Shanshan An,Fei Ren,Xiuhong Ge,Lang Cheng,Feiyan Yang,Hongzhi Pan,Shengzhong Rong,Dong Chang,Hongkun Ma

Survivin serves as a crucial biomarker for bladder cancer, so exploring the detection method is essential. Therefore, a sensitive ratiometric electrochemical immunosensor was developed. In brief, a double-layered amino graphene oxide (NH 2 -GO) sandwich enhanced by Fe-Ni@Ti 3 C 2 T x (NH 2 -GO/Fe-Ni@Ti 3 C 2 T x /NH 2 -GO) significantly amplified the detection signal. ferrocene@Au nanoparticles (Fc@AuNPs) provided a reference signal, and Ab 1 was anchored via an Au-N bond. Moreover, AuPt-methylene blue (AuPt-MB) served not only as a secondary signal but also anchored Ab 2 through Au-NH 2 and Pt-NH 2 bonds. Black phosphorus nanoplates (BPNPs) improved conductivity and provided additional binding sites for AuPt-MB. The immunosensor exhibited a broad detection range (0.001~1000   ng/mL) and a low detection limit (0.00065   ng/mL), facilitating successful survivin detection in human urine samples with promising clinical analysis applications.

Dual-product synergistically enhanced ratiometric fluorescence assay for alkaline phosphatase activity using core-shell lanthanide-based nanoprobe

Tian-Tian Cai,Yao Tian,Pengcheng Huang,Fang-Ying Wu

We developed a new core-shell ratiometric fluorescent nanoprobe simply prepared by a seeded growth method. The strong luminescence arising from the shell formed by coordination self-assembly of an alkaline phosphatase (ALP) substrate, l -ascorbic acid 2-phosphate (AAP), and Tb 3+ , together with the weak fluorescence of the core-a metal-organic framework, UiO-66-NH 2 , constitutes an ideal dual-emission characteristic. Since AAP can be specifically cleaved by ALP, the well-formulated core-shell nanostructure was destroyed upon exposure to ALP. In this case, the luminescence of Tb 3+ was quenched due to the inefficient antenna effect, while the fluorescence of UiO-66-NH 2 was strengthened by the synergistical enhancement of dual hydrolysates to inhibit the ligand-to-metal charge transfer (LMCT) process. Using the dual signal response, this nanoprobe was employed for ratiometric fluorescence detection of ALP activity in the range of 0.05–0.6 U mL −1 with a detection limit of 0.018 U mL −1 , accompanied by a discernible fluorescence color evolution from turquoise to blue. In virtue of good properties in accuracy, sensitivity, selectivity and simplicity, this assay enabled quantitative detection of ALP activity in human serum and efficient screening of ALP inhibitors. More Importantly, a smartphone-assisted paper-based sensing platform was designed for on-site visual analysis of ALP activity in human serum, which may be very promising as a facile, portable, and robust format to facilitate relevant biological and clinical applications.

Novel Transparent TiO2/AgNW–Si(NH2)/PET Hybrid Films for Flexible Smart Windows

Tingting Hao,Shen Wang,Hongbo Xu,Xiang Zhang,Shlomo Magdassi,Lei Pan,Ying Song,Yao Li,Jiupeng Zhao

The application of flexible indium tin oxide (ITO)-free electrochromic devices (FCDs) has always been a research hotspot in flexible electronics. Recently, a silver nanowire (AgNW)-based transparent conductive film has raised great interest as an ITO-free substrate for FCDs. However, several challenges, such as the weak binding of AgNWs to the substrate, high junction resistance, and oxidation of AgNWs, remain. In this paper, a novel method for surface modification of AgNWs with N-aminoethyl-γ-aminopropyltrimethoxysilane [Si(NH2)] solution is proposed to enhance the bonding with the flexible substrates and the active materials, thereby inhibiting the delamination of AgNWs from the substrate and reducing the high junction resistance between nanowires. The TiO2/AgNW–Si(NH2)/poly(ethylene terephthalate) (PET) films show outstanding mechanical properties, of which the resistance remains almost unchanged after mechanical bending of 5000 cycles (ΔR/R0 ≈ 3.6%) and repeated peeling off cycles with 3M tape 100 times (ΔR/R0 ≈ 6.0%). In addition, we found that the oxygen-containing groups on the TiO2/AgNW–Si(NH2)/PET surface form hydrogen bonds with the TiO2 sol, resulting in tight contact between the TiO2 sol and the AgNWs, which prevents the AgNWs from oxidation. As a result, the TiO2/AgNW–Si(NH2)/PET film exhibited long-time aging (ΔR/R0 ≈ 4.9% in the air for 100 days) stability. A FCD was constructed with the TiO2/AgNW–Si(NH2)/PET film, which showed excellent electrochromic performance (94% retention) after 5000 bending cycles, indicating high stability and mechanical flexibility. These results present a promising solution to the transparent conductive films for flexible energy devices.

Conversion of ethyl levulinate to γ-valerolactone catalyzed by Pd/UiO-66-NH2

Ying Gao,Jinxing Long

Conversion of ethyl levulinate to GVL was proposed using Pd 4 /UiO-66-NH 2 . • Pd 4 /UiO-66-NH 2 was constructed via a post-synthetic modification strategy. • Synergistic effects between Pd species and acidic sites drive superior performance. • GVL yield of 90% with 98.9% selectivity was achieved under 170 ℃ and 1.0 MPa H 2 . • The catalyst shows good recyclability, and can be reused for at least five runs. An efficient strategy is proposed for direct hydrogenation of ethyl levulinate (EL) to γ-valerolactone (GVL) using a highly dispersed palladium nanoparticles supported on the UiO-66-NH 2 framework (Pd/UiO-66-NH 2 ), which was prepared via a facile post-synthetic modification by anchoring palladium (Pd) nanoparticles on the framework's native -NH 2 groups. Under optimized conditions (170 °C, 1.0 MPa H 2 ), 90% yield and 98.9% selectivity of GVL were shown when the reaction was catalyzed by Pd 4 /UiO-66-NH 2 in cyclohexane. Catalyst characterization using XRD, N 2 adsorption-desorption, FT-IR, TEM, TGA, XPS and H 2 -TPR, confirmed that an intensive synergistic effect existed between the Pd and the acidic sites, which is responsible for the superior performance of Pd@UiO-66-NH 2 . The solvent effect and the feedstock adaptability were also investigated. Furthermore, the catalyst of Pd 4 /UiO-66-NH 2 demonstrated good stability and reusability, where no significant activity loss was shown even after five consecutive cycles. Therefore, this study provides new insights for efficient upgrading biochemical. Download: Download high-res image (188KB) Download: Download full-size image

Metal–organic cages ZrT-1-NH2 for rapid and selective sensing of nitrite

Xin Yang,Xin-Yi Yu,Qing Wang,Jie Zou,Gui-Ping Liao,Meng-Tian Li,Xin-Li Liu,Hui Xia,Fu-Jian Xu

Herein, a label-free, sensitive, and selective fluorescence probe for the detection of trace nitrite in water sample by metal–organic cages (ZrT-1-NH 2 ) was reported. The fluorescence emission of as-prepared ZrT-1-NH 2 was 450 nm upon the excitation of 373 nm with a quantum yield of about 8.6%, which can be quenched by the addition of nitrite. The proposed sensor owned the advantages of high sensitivity (limit of detection = 0.5 µM), quick response (100 s), and excellent selectivity in the presence of various ions. The fluorescence quenching was due to the diazotization and reduction reaction of –NH 2 with the preliminary studying. Under the optimized condition, the sensor was successfully exemplified by real water samples and comparative performance was achieved.

ZIF-8@NENP-NH2 embedded mixed matrix composite membranes utilized as CO2 capture

Xinru Zhang,Xiaofeng Ren,Yonghong Wang,Jinping Li

Mixed matrix composite membranes (MMCMs) for CO 2 capture have great potential in carbon neutral goal. However, simultaneous enhancement in permeance and selectivity is very difficult, since mismatching pore and chemical structures of filler with polymer matrix are the stumbling block. Herein, novel core–shell MOFs@COFs hybrids were prepared by growing hierarchical pore covalent organic frameworks (COFs, nitrogen-enriched nanoporous polytriazine (NENP)) on the surface of metal organic framework (MOFs, zeolite imidazolate framework-8 (ZIF-8)), where ethylenediamine were impregnated into NENP pore to adjust the chemistry environment of the shell. Subsequently, a porous polysulfone (PSf) membrane-supported MMCMs were developed by a coating method using a mixed dispersion of ZIF-8@NENP-NH 2 and polyvinylamine (PVAm), which was used to efficiently separate CO 2 from N 2 . The rough COFs layer (NENP-NH 2 ) was closely wrapped on the smooth surface of ZIF-8 as identified by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and N 2 adsorption. Even-distributed ZIF-8@NENP-NH 2 had well miscibility with the PVAm matrix from hydrogen bonding as evidenced by SEM, attenuated total reflectance-FTIR and differential scanning calorimetry. The CO 2 permeance as high as 301 GPU accompanied with a selectivity of 91 was obtained for MMCMs loaded with 7 wt% ZIF-8@NENP-NH 2 , which were enhanced by 296.1% and 89.6%, respectively, when compared with the pristine PVAm membrane, transcending 2019 upper bound. We assume that the surface chemistry environment in hierarchical pore of the shell and molecular sieving pore in the core in the short-range order facilitate CO 2 permeation. Furthermore, this membrane maintained an average CO 2 permeance of 369 GPU and a CO 2 /N 2 selectivity of 97.3 for over 360 h using CO 2 /N 2 mixed gas as feed gas.

Efficient Immobilization of Enzymes on Amino Functionalized MIL-125-NH2 Metal Organic Framework

Wang Zichen,Liu Yang,Li Jinhong,Meng Guoqing,Zhu Daoyu,Cui Jiandong,Jia Shiru

As a series of metal organic framework (MOFs), materials of institute lavoisier frameworks (MILs) are expected to be excellent supports for enzyme immobilization due to their good water-stability and acid tolerance. However, enzyme loading on MIL-125-NH 2 is very low due to small pore size and few amino groups on the surface of the MIL-125-NH 2 . In this work, catalase (CAT) was immobilized on the MIL-125-NH 2 and amino functionalized MIL-125-NH 2 by adsorption (CAT@MIL-125-NH 2 ) and covalent binding (CAT@Amino MIL-125-NH 2 ), respectively. Compared with the CAT@MIL-125-NH 2 and free CAT, the CAT@Amino MIL-125-NH 2 displayed high activity recovery, good pH stability, stability against denaturants, and thermostability. Furthermore, activity recovery of CAT@Amino MIL-125-NH 2 was 56% higher than CAT@MIL-125-NH 2 . The CAT@Amino MIL-125-NH 2 still retained 50% residual activity for 14 days at room temperature, whereas free CAT lost activity after storage for 1 day at the same storage conditions. Furthermore, the CAT@Amino MIL-125-NH 2 maintained 62% of its initial activity after 4 consecutive uses, showing good reusability. The results showed that the amino functionalized MIL-125-NH 2 is an excellent carrier of enzyme immobilization.

Adsorption of phosphate on UiO-66-NH2 prepared by a green synthesis method

Xiaoting Zhang,Mingyu Liu,Runping Han

In this study, a zirconium-based metal organic framework (UiO-66-NH 2 ) was prepared with a green synthetic method for removal of phosphate from solution. Several characterization methods were performed and the adsorption property of UiO-66-NH 2 toward phosphate was explored in batch mode. There was a good adsorption performance for phosphate with a wide range of pH (pH = 2–11) with a slight effect of salinity . The adsorption capacity was up to 43.9 mg·g –1 at 303 K from experiments. The adsorption isotherms can be better described by Langmuir, Temkin, and Koble-Corrigan model while adsorption kinetics can be well fitted by Pseudo-second-order, Double Constant and Elovich model. The process was spontaneous and exothermic and the major mechanism of phosphate adsorption was complexation. The spent adsorbent can be well regenerated using 0.01 mol·L –1 NaOH. The study shows that UiO-66-NH 2 has the potential to remove phosphate from solution.

Biomimetic photocatalyst Ce/TCPP-UiO-66-NH2 for NADH regeneration and CO2 activation

Hao Guo,Likun Luan,Jinde Cai,Xiuling Ji,Haijun Yu,Yuhong Huang

CO 2 activation and conversion by enzymes to produce value-added multi-carbon compounds under mild conditions show significant impact on carbon neutrality. However, the enzyme co-factor NADH is expensive and the regeneration is still challenging for the enzyme reaction process. Inspired by natural photosynthesis, this study successfully developed a biomimetic photocatalyst Ce/TCPP-UiO-66-NH 2 (TCPP: meso-tetrakis (4-carboxyphenyl) porphine) for NADH regeneration and CO 2 activation. Structure analysis and spectra showed that the co-doping of Ce and TCPP reduced the band gap width of UiO-66-NH 2 , improved the separation efficiency of photo-generated carriers, and endowed it with excellent photocatalytic performance. The synthesized biomimetic photocatalyst Ce/TCPP-UiO-66-NH 2 was then applied for NADH regeneration. The regeneration efficiency of NADH can reach up to 95 % after 3 h of light reaction, which was about 1.6 times higher than that of the control group. Ultra-fast femtosecond time-resolved transient absorption (fs-TA) showed that Ce/TCPP-UiO-66-NH 2 possessed the shortest average decay time ( τ ¯ $\overline{\tau }$  = 1.12 ps), indicating shorter average life-time of carriers after Ce doping, thus suppressing hole-electron recombination. Finally, the key enzyme formate dehydrogenase (FDHPa) for CO 2 activation was immobilized on the membrane, combining with light regeneration of NADH for CO 2 production to formate. The formate yield (3.1 mM) was 16 times higher than that of the control group (0.19 mM). This work provided an effective strategy and efficient photocatalyst for the biomimetic photocatalytic activation of CO 2 to formate, which is an indispensable bridge for the further high-valuable C n compounds production by biocatalysis.

Ratio fluorescence detection of tetracycline by a Eu3+/NH2-MIL-53(Al) composite

Jing Chen,Yali Xu,Shuying Li,Fanghong Xu,Qian Zhang

Tetracycline detection has been a great concern because of its overuse and difficulty in degrading. Here, a detection method with ratio fluorescence was developed by synthesizing Eu3+ doped nanocomposites with NH2-MIL-53(Al) nanosheets. After adding tetracycline, the fluorescence intensity at 616 nm characteristic emission peak of Eu3+ was sensitized by the antenna effect generated from coordinating Eu3+ with tetracycline, but the fluorescence of NH2-MIL-53(Al) at 433 nm was quenched by the fluorescence resonance energy transfer between the Eu3+-tetracycline composition and NH2-MIL-53(Al). Therefore, the efficient detection of tetracycline was achieved based on this change of ratio fluorescence signal. The experimental results show that Eu3+/NH2-MIL-53(Al) has excellent selectivity, a wider linear range and a lower detection limit for detecting tetracycline. This method can afford favorable ideas for developing advanced chemical and biological sensors.

Effective toluene adsorption over defective UiO-66-NH2: An experimental and computational exploration

Xiaoyu Shi,Xiaodong Zhang,Fukun Bi,Zenghui Zheng,Lijun Sheng,Jingcheng Xu,Zhong Wang,Yiqiong Yang

In this thesis, defective UiO-66-NH 2 using cetyltrimethylammonium bromide (CTAB) as a template was successfully synthesized. The toluene adsorption-desorption properties were studied using breakthrough experiments and temperature programmed desorption (TPD). Modified UiO-66-NH 2 showed a high toluene increase due to the increased specific surface area and total pore volume and extra accessible adsorption sites generated by defects. Additionally, adsorption mechanisms were discussed at micro and molecule levels in light of density functional theory (DFT) calculations. By calculation, the amino hydrogen bonding gave rise to a higher toluene adsorption over UiO-66-NH 2 . In terms of the modified UiO-66-NH 2 with the most deficiencies, synergistic effects among π-π, -NH 2 , OH-CH 3 and OH-π hydrogen bonding strength also significantly intensified toluene adsorption. Furthermore, it could be noted that the OH-π interaction was stronger than the two bonded μ 3 -OH mechanisms. Notably, TPD and binding energies (BEs) depicted that defective UiO-66-NH 2 had a weaker toluene affinity than did UiO-66-NH 2 . Thus, gas toluene was easy to desorb with defective UiO-66-NH 2 at 298 K under atmospheric pressure. Finally, the repetitive regeneration experiment showed that the reproducibility of the materials was excellent.

Adsorption of Cr (VI) onto Attapulgite/UiO-66-NH2 Composites from Aqueous Solution

Peiyi Bao,Haiying Du,Xiangning Xu,Junya Li,Yao Wu,Shaojiang Zhou,Lingyun Li,Ningfei Lei