查找使用阿拉丁产品的科研文献

Enhanced Antibody Immobilization Through a Site-Oriented Process Integrated with Surface Modification

Li Liping,Liu Xiaojia,Xiao Qian,Zheng Yizhi,Wang Suiping,Feng Bo

A novel antibody immobilization method was developed for enzyme-linked immunosorbent assay (ELISA). The proposed method utilizes amine-bearing polymer macromolecules, namely, polyamidoamine (PAMAM) or polyethylenimine (PEI) to enhance antibody binding on polystyrene (PS) microwells, as well as staphylococcal protein A (SPA) to realize orientation immobilization. After carboxylating the PS microwells with the solution of potassium permanganate (KMnO4) in diluted sulfuric acid (H2SO4), the PS surface was activated by 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide and then grafted with PAMAM or PEI to introduce free amino groups. Glutaraldehyde was subsequently added to conjugate the amino groups and SPA prior to antibody adsorption. X-ray photoelectron spectroscopy and atomic force microscopy were performed to investigate the morphology of the PS surfaces before and after different treatments. The immunoglobulin binding sites were confirmed through anti-Fab and anti-Fc ELISA kits. Results from the alpha fetoprotein ELISA kit showed that the use of both PAMAM and SPA is the optimal method for antibody immobilization. In this treatment, absorbance exhibited an evident gradient with antigen concentrations and reached higher values over 200 ng/mL antigen compared with the ones of other methods.

Superior High-Temperature Energy Density in Molecular Semiconductor/Polymer All-Organic Composites

Bin Zhang,Xiao-ming Chen,Zhe Pan,Peng Liu,Minmin Mao,Kaixin Song,Zhu Mao,Rong Sun,Dawei Wang,Shujun Zhang

High-temperature dielectric polymers are in constant demand for the multitude of high-power electronic devices employed in hybrid vehicles, grid-connected photovoltaic and wind power generation, to name a few. There is still a lack, however, of dielectric polymers that can work at high temperature (> 150 °C). Herein, a series of all-organic dielectric polymer composites have been fabricated by blending the n-type molecular semiconductor 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA) with polyetherimide (PEI). Electron traps are created by the introduction of trace amounts of n-type small molecule semiconductor NTCDA into PEI, which effectively reduces the leakage current and improves the breakdown strength and energy storage properties of the composite at high temperature. Especially, excellent energy storage performance is achieved in 0.5 vol.% NTCDA/PEI at the high temperatures of 150 and 200 °C, e.g., ultrahigh discharge energy density of 5.1 J cm −3 at 150 °C and 3.2 J cm −3 at 200 °C with high discharge efficiency of 85–90%, which is superior to its state-of-the-art counterparts. This study provides a facile and effective strategy for the design of high-temperature dielectric polymers for advanced electronic and electrical systems.

Preparation and Cr (VI) adsorption of functionalized polyimide fibers

Wei Jia,Jiang Du,Ming Jiang,Mengying Zhang,Enlin Han,Hongqing Niu,Dezhen Wu

In order to overcome the shortcomings of nanofiber membranes such as low mechanical properties and poor acid resistance, amino-rich functionalized polyimide (PI)-polyethyleneimine (PEI) fibers were successfully prepared in the study. The structure and morphology in each functionalization step were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), static contact angle, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), and X-ray photoelectron spectroscopy (XPS) measurements. The adsorption kinetics analysis showed that the adsorption process followed a pseudo-second-order model, and the adsorption isotherm could be described better by the Langmuir model indicating the adsorption process was mainly chemical and homogeneous monolayer adsorption. Furthermore, the maximum adsorption capacity based on the Langmuir model was about 50 mg g −1 , and the calculated thermodynamic parameters demonstrated an endothermic process. Meantime, the PEI-grafted PI fibers also exhibited good regeneration performance and stable tensile strength during recycling tests process. In the first 3 adsorption–desorption cycles, the removal efficiency and tensile strength of PI-PEI fibers could be maintained up to 60.44% and 89.29% of the initial adsorption, respectively. This work achieved the function of removing Cr (VI) by combining the excellent high temperature resistance, acid resistance, and mechanical properties of PI fibers.

Property-Tunable 1,2-Epoxybutane-Modified Poly(Ethylene Imine) (nEB-PEI): Volumetric and Viscometric Properties of CO2-Free and Loaded Aqueous Solution at Different Temperatures

Chen Yuhuan,Chen Jing,Chen Chunhong,Yang Fang

In this work, n EB-PEI 1800 ( n  = 0.22, 0.29, 0.35), a property tunable polymer for CO 2 capture, is reported by partially modifying poly (ethylene imine) (PEI 1800 ) with 1,2-epoxybutane (EB). The density and viscosity of CO 2 -free and loaded aqueous n EB-PEI 1800 solution are measured at the temperatures of (293.15 to 333.15) K and 0.1 MPa. The aqueous solutions with various weight fractions of w  = (5, 10, 15, 20 and 30%) are investigated. According to the experimental data, thermal expansion coefficient ( α p ), viscosity activation energy ( E η ) and CO 2 diffusion coefficient ( D CO2 ), are calculated. The influence of temperature, n EB-PEI concentration, CO 2 loading and modification degree are discussed from the viewpoints of molecular interaction and steric effect. The results reveal that low temperature, high n EB-PEI concentration and high CO 2 loading lead to high density and viscosity. Modification degrees have a great impact on the physical properties of n EB-PEI 1800  + H 2 O systems and can reduce the density and viscosity. The density and viscosity values exhibit the decreasing sequence of ρ PEI + H2O  >  ρ 0.29EB-PEI + H2O  >  ρ 0.35EB-PEI + H2O ≈ ρ 0.22EB-PEI + H2O and η PEI + H2O  >  η 0.22EB-PEI + H2O  >  η 0.35EB-PEI + H2O  >  η 0.29EB-PEI + H2O , respectively. All the results are attributed to the combined effects of hydrogen bonding, dispersion force and steric structure.

A Novel Photo-Responsive and Platelet-Compatible Strategy Based on Fe3O4-QCS-PEI-Cu and Aptamer for Targeted Inactivation of Bacterial Contaminants in Platelets

Bacterial contamination remains a critical safety concern in platelet transfusion, and there is an urgent demand for decontamination technologies that eliminate contaminating bacteria without damaging platelet viability and physiological function. Herein, Fe3O4-QCS-PEI-Cu-apt microparticles with enlarged magnetic cores were rationally fabricated to improve aptamer immobilization, aiming at targeted bacterial elimination via near-infrared (NIR) irradiation while maintaining platelet function. Fluorescence assays confirmed their specific targeting capability towardStaphylococcus aureus(S. aureus) without binding to platelets. Magnetic separation experiments demonstrated that the aptamer-functionalized microparticles could efficiently capture and remove 91.35% ofS. aureusfrom platelets. NIR irradiation of the Fe3O4-QCS-PEI-Cu core induced marked bactericidal activity againstS. aureusin suspension, as determined by plate counting and LIVE/DEAD staining. This antibacterial ability originated from the intrinsic photo-responsive property of the composite rather than from aptamer-mediated recognition, and could be easily extended to bacteria captured by aptamer-functionalized particles. Comprehensive biocompatibility evaluations, including morphological observation, hematological parameter analysis, CD62P expression detection, and thromboelastography (TEG) were performed. And the results demonstrated that there were no significant changes in platelet morphology, count, activation state, or overall hemostatic function, apart from an increase in the α angle. This platform achieves efficient targeted NIR-triggered antibacterial efficacy while maintaining excellent platelet compatibility, offering a promising strategy to enhance the safety of platelet transfusion.

3D-printed porous PEI/TCP composite scaffolds loaded with graphdiyne oxide on the surface for bone defect repair and near-infrared light-responsive antibacterial

Hao Wang,Xinyu Xu,Xiaohan Mei,Dapeng Zeng,Boda Ying,Zehao Yu,Shibo Liu,Ruiyan Li,Yanguo Qin

Bone implants that promote osseointegration and have antimicrobial capabilities are necessary to ensure optimal long-term functionality of implants. In this study, a porous composite osteogenic scaffold was prepared using a twin-screw extruder and a fused deposition modeling three-dimensional (3D) printer. A polydopamine (PDA) coating was used to load graphdiyne oxide (GDYO) on the surface of the 3D printed polyetherimide-tricalcium phosphate (PEI-TCP) osteogenic scaffold through π–π double-bond interactions. The resulting P-T-GDYO composite scaffold was characterized, and its mechanical properties, ability to promote osteogenic differentiation, and light-responsive antibacterial activity were evaluated. When the scaffold was doped with 10 wt% β-TCP, its mechanical properties remained in the range of those of cancellous bone. In terms of osteogenic differentiation, the P-T-GDYO composite scaffold promoted adhesion and osteogenic differentiation of MC3T3-E1 cells, as well as effectively promoting endogenous bone regeneration of rabbit femoral condyle bone defects in osteogenesis experiments in vivo . In a mouse subcutaneous infection model, after near-infrared light irradiation, P-T-GDYO showed an antibacterial rate of 90.18 % against Staphylococcus aureus , while maintaining good tissue–organ compatibility. This study represents an important development in GDYO-based photothermal antibacterial materials in the field of orthopedics and expands its application in the biomedical field.

A SERS-Fluorescence dual-signal aptasensor for sensitive and robust determination of AFB1 in nut samples based on Apt-Cy5 and MNP@Ag-PEI

Haoyang He,Da-Wen Sun,Hongbin Pu,Zhihui Wu

Food aflatoxin B1 (AFB1) contamination greatly threatens human health and its sensitive determination is imperative. In this study, a surface-enhanced Raman scattering (SERS) and fluorescence dual-signal aptasensor was constructed for sensitive AFB1 detection in peanuts, walnuts, and almonds samples. Fluorescent dye cy5 was used as fluorophore and Raman reporter, while polyethyleneimine modified Ag coating magnetic nanoparticles (MNP@Ag-PEI) were utilized to absorb the cy5 modified aptamer (apt-cy5). Results indicated that linear ranges of 0.001–1000 ng/mL and 0.2–20,000 ng/mL with detection limits of 0.45 pg/mL and 0.135 ng/mL for the SERS and fluorescence methods were obtained, respectively, and AFB1 detection in the nut samples using the aptasensor achieved satisfactory recoveries of 95.2%–108.6% for SERS and 94.7%–109.7% for fluorescence. Compared with other mono signal detection, the established aptasensor facilely fused the merits of the two signals and improved the detection accuracy and flexibility.

Preparation of PVA/PEI/CNC/ZnO composite membrane with good mechanical properties and water resistance by electrostatic spinning using for efficient filtration of PM2.5

Jingda Huang,Shite Lin,Yipeng Liang,Enfu Wang,Yu Miao,Wenbiao Zhang,Kuichuan Sheng

It is still a serious challenge to construct a water-soluble polymer-based air filtration membrane with high efficiency and good mechanical properties by electrospinning. In the study, using polyvinyl alcohol (PVA) and polyacetylimide (PEI) as the main materials, both nanocellulosic crystal (CNC) and zinc oxide (ZnO) as the synergistic reinforcers and methyltrimethoxysilane (MTMS) as the hydrophobic modifier, the electrospun PVA/PEI/CNC/ZnO composite nanofibrous membrane with dual air filtration mechanisms was established. One of the mechanisms was the interception of the three-dimensional network structure built by the composite nanofibrous membrane, the other was the electrostatic adsorption provided by CNC. Based on the dual air filtration mechanisms, the filtration efficiency of particulate matter 2.5 (PM2.5) reached 98.20%. Moreover, the composite nanofibrous membrane displayed a good thermal stability and could still maintain more than the filtration efficiency of 83% and low-pressure drop after treatment at 200 °C for 1 h. Moreover, the composite nanofibrous membrane could still maintain the filtration efficiency (97.3%) and low-pressure drop (110.7 Pa) after five washing cycles after filtration, reflecting good reusability. Interestingly, the PVA/PEI/CNC/ZnO composite nanofibrous membrane was simple to produce and demonstrated excellent filtration efficiency, as well as excellent thermal stability, which could be an effective barrier against PM2.5 invasion. Graphical

A SERS bioassay based on vancomycin-modified PEI-interlayered nanocomposite and aptamer-functionalized SERS tags for synchronous detection of Acinetobacter baumannii and Klebsiella pneumoniae

Clement Yaw Effah,Lihua Ding,Longlong Tan,Sitian He,Xiang Li,Huijie Yuan,Yi Li,Shaohua Liu,Tongwen Sun,Yongjun Wu

Klebsiella pneumoniae ( KP ) and Acinetobacter baumannii ( AB ) are two important gram-negative bacteria that cause pneumonia and have been recently known to be associated with food. The rapid detection of these pathogens in food is important to minimize their colonization of the gut and stop new threats of the disease from spreading across the food chain. Herein, a double-edged sword aptasensor was developed for the synchronous detection of KP and AB in food and clinical samples. A highly sensitive, selective, specific, and synchronous detection of the target bacteria was achieved, and the limit of detection (LOD) was 10 cells/mL with a liner range of 50 to 10 5 cells/mL. The total assay time was 1.5 h. This study does not only provide a new tool for the detection of the target bacteria, but also serves as a promising tool for food safety and pneumonia diagnosis.

A novel self-enhanced electrochemiluminescence sensor based on PEI-CdS/Au@SiO2@RuDS and molecularly imprinted polymer for the highly sensitive detection of creatinine

Nian Cao,Faqiong Zhao,Baizhao Zeng

In this work, a novel self-enhanced solid state electrochemiluminescence (ECL) platform, based on polyethyleneimine (PEI) capped CdS quantum dots (PEI-CdS QDs) as coreactant and [email protected] 2 @Ru(bpy) 3 2+ doped silica ( [email protected] 2 @RuDS) nanocomposite as ECL emitter, was constructed. The PEI-CdS QDs integrated double coreactant of PEI and CdS QDs, thus significantly promoted the ECL of [email protected] 2 @RuDS. Polyaniline hydrogel was introduced to boost the electron transfer and to improve the immobilization of PEI-CdS/ [email protected] 2 @RuDS. In addition, creatinine imprinted poly(o-aminophenol) film was electrodeposited on the PEI-CdS/ [email protected] 2 @RuDS surface as recognition element. Thus, the obtained sensor possessed high sensitivity, stability, reproducibility and selectivity for creatinine sensing. The change of ECL intensity and logarithm of creatinine concentration showed a good linear relationship in the range of 0.05 nM to 5 μM, and the detection limit was low to 0.02 nM. The sensor was applied to detect creatinine in human serum and urine samples, and the results were in good agreement with those of commercial enzyme-linked immunosorbent assay kit.

In situ growth of Rh nanoparticles with controlled sizes and dispersions on the cross-linked PVA–PEI nanofibers and their electrocatalytic properties towards H2O2

Han Zhu,Ming Zhang,ShengYing Cai,YingTing Cai,Pan Wang,ShiYong Bao,MeiLing Zou,MingLiang Du

A facile approach for the synthesis of uniform, small size and well-dispersed rhodium nanoparticles (RhNPs) on cross-linked polyvinyl alcohol–polyethyleneimine (PVA–PEI) nanofibers has been demonstrated. Various methods were firstly employed to cross-link PVA nanofibers and the cross-linked PVA–PEI nanofibers exhibited good water stability and porous structures after immersing in water for 72 h. Because of the strong chelate effects among the amine groups, hydroxyl groups and Rh3+ ions, uniform RhNPs with an average diameter of about 2.5 ± 0.2 nm can evenly and densely grow throughout the PVA–PEI nanofibers via an in situ reduction. Meanwhile, the better dispersion and smaller size of the RhNPs grown on the nanofibers in comparison with the pre-synthesized RhNPs directly deposited on the nanofibers exhibit the advantages of in situ reduction for size and dispersion control. The successful fabrication of the RhNPs/(PVA–PEI) nanofibers with various densities of well-dispersed RhNPs demonstrates that the strong chelate effects and stabilization of the PVA–PEI nanofibers also play an essential role in the size and dispersion control of RhNPs. The crystal structures, chemical bonding and interactions of the prepared nanofibers were verified using XPS and FTIR spectra and XRD patterns. These novel nanomaterials were fabricated as non-enzymatic electrochemical sensors and exhibit highly electrocatalytic activity towards H2O2.

Ultratrace Naked-Eye Colorimetric Detection of Hg2+ in Wastewater and Serum Utilizing Mercury-Stimulated Peroxidase Mimetic Activity of Reduced Graphene Oxide-PEI-Pd Nanohybrids

Shouting Zhang,Dongxu Zhang,Xuehong Zhang,Denghui Shang,Zhonghua Xue,Duoliang Shan,Xiaoquan Lu

Herein, we developed a general strategy for rapid, highly selective, and ultratrace naked-eye colorimetric detection of Hg2+ in aqueous solutions. Two dimensional rGO/PEI/Pd nanohybrids, where rGO, PEI, and Pd were referred to as reduced graphene oxide, polyethylenimine, and Pd nanoparticles, respectively, were synthesized and used as mimetic peroxidase for selective and ultrasensitive detection of Hg2+ in water and human serum samples. In the presence of mercury ions, the peroxidase mimetic activity of rGO/PEI/Pd nanohybrids was found to be stimulated and enhanced significantly, which promoted the effective oxidation and color change of 3,3′,5,5′-tetramethylbenzidine (TMB) in solution to dark blue that was detected by the naked-eye and the absorption spectroscopic method. The proposed sensing strategy coupled with spectroscopic detection method showed an ultralow detection limit of 0.39 nM for Hg2+ in ddH2O and ∼1 nM in wastewater as well as serum samples, respectively. On the basis of the colorimetric assay, a minimum concentration of ∼10 nM for Hg2+ in wastewater and human serum can be detected with the naked-eye. The naked-eye-based colorimetric assay for sensitive and selective detection of mercury is expected to hold huge potentials in applications such as environmental monitoring, clinical diagnosis, and pharmaceutical analysis.