APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Yiqiang Sun,Chenchen Wang,Yong Wang,Yuan Xu,Xiaodong Yang,Bo Ouyang,Cuncheng Li
Water splitting, one of the primary strategies for advancing the utilization of hydrogen production, necessitates the input of external energies to initiate the reaction due to its thermodynamically uphill nature. Nevertheless, Ru-based compounds, which were widely used as benchmark anodic catalysts, facing significant drawbacks such as their susceptibility to dissolution, significantly restrict the overall water splitting efficiency. In this work, we introduce an approach for functionalization through combining Ru nanospheres with Ir to form a Ru@Ir core–shell structure (denoted as Ru@Ir core–shell NSs), which can activate the superior oxygen evolution reaction (OER) catalytic activity, and simultaneously inherit the hydrogen evolution reaction (HER) performance in all-pH condition. The work function difference between Ru and Ir promotes the necessary energetic impetus for electron migration from Ru to Ir, resulting in the charge redistribution. Density functional theory (DFT) calculations confirmed that the Ir shell, acting as an electron acceptor, could effectively trigger electron rearrangement, augmenting the ligand affinity of hydrogen and oxygen intermediates to attain the most favorable energy states, thereby accelerating the kinetics of hydrogen and oxygen evolution. Our suggested core–shell structure approach for manipulating interface charge distribution might find utility in creating other electrocatalysts for water splitting.
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES COMMUNICATIONS
·
2021
·
IF 6.617
Lu Wu,Yunping Hu,Ping Tang,Hai Wang,Yuezhen Bin
Graphene and its derivatives are considered as one of the most promising functional materials due to their excellent mechanical and electrical properties. Here, we successfully prepared uniform and long-term stable reduced graphene oxide (rGO) dispersion using sodium carboxymethylcellulose (CMCNa) as a stabilizer creatively, and fabricated rGO/CMCNa/polyacrylic acid (PAA) conductive composite hydrogel. The optimal elongation at break of the cylindrical composite hydrogel (1 cm in diameter and 4 cm in length) could reach 1200% at a tensile rate of 50 mm/min. The swelling rate of the composite hydrogel in alkaline environment was much higher than that in acidic environment, indicating excellent pH sensitivity. More importantly, the conductivity of the composite hydrogel could be increased by about 2500% and reached 0.56 S/m due to the construction of the rGO conductive network. The strain sensor based on the rGO/CMCNa/PAA hydrogel showed a wide region of linear response to deformation, up to a strain of 300%. It also exhibited good performance in other aspects, including low hysteresis, a GF value of 1.0, a short response time of 187 ms, and satisfactory stability and repeatability of 2000 cycles at 50% strain. In particularly, the strain sensor could be well adhered to skin without any other adhesives as soft human-motion sensor for real-time and accurate detection of both large-scale and subtle human activities, indicating a great application potential in electronic skin and human health detection.
✓ 已验证
产品关联
DOI
高影响因子
NANOTECHNOLOGY
·
2021
·Vol. 32
·期 17
·175604
·
IF 3.874
Fan Liu,Yuan Jiang,HaiBao Shao,Chunlei Wang,Shuhong Xu,Rong Zhang
Precise control of the structure and bonds of doped carbon dots (CDs) is important, so that their fluorescence can be tuned as desired. Up until now, there has been a lack of effective ways to control the bonds of doped CDs. In this article, we show that the fluorescence of B/N-doped carbon dots (B/N-CDs) can be precisely tuned just by controlling their precursors' pH values. The prepared B/N-CDs exhibit two emission bands, including one emission peak at around 450 nm due to the defect state caused by low sp2 hybridization of carbon atoms, as well as another emission peak at around 360 nm caused by the B-N bond. The results for the ratio of the maximum intensity of the two emission peaks above show a linear relationship. Meanwhile, the role of the pH value of the precursors on the luminescence of B/N-CDs is deeply studied. On the one hand, the pH value affects the bonding process of CDs. N-H bonds tend to form at a low pH value, while more competitive B-N bonds exist at much higher pH value, leading to the pH-dependent intensity of the 360 nm emission band. On the other hand, a high pH value causes higher crystallinity, thus suppressing defect-state fluorescence at 450 nm. The dual effects of pH lead to precisely controlled dual-emission intensities as well as ratiometric fluorescence.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2021
·
IF 5.279
Shanshan Tie,Wentao Su,Xuedi Zhang,Yannan Chen,Xue Zhao,Mingqian Tan
The purpose of this study was to construct a delivery system using a microfluidic chip to protect procyanidins (PCs) and to achieve their pH-controlled release in simulated gastrointestinal fluid. The microfluidic chip was designed and fabricated to generate water-in-water-in-oil (W/W/O) templates for the preparation of sodium alginate/chitosan microparticles with a uniform size and core–shell structure, using an internal–external gelation method. Compared with free PCs, the stability of PCs embedded in microparticles was improved and a pH stimulus-responsive release of PCs from microparticles was observed under neutral pH conditions. The delivery system of microparticles was nontoxic and showed an inhibitory effect on the decrease of mitochondrial membrane potential in Caco-2 cells caused by H2O2 and acrylamide. This work provided a method for fabricating compact microfluidic chips to prepare a pH stimulus-responsive PCs delivery system with improved stability, which may have potential applications in the delivery of other nutrients.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2021
·Vol. 28
·期 26
·35113-35125
·
IF 4.223
An Shaorong,Jin Qiang
In recent years, the excess discharge of ammonia nitrogen from wastewater into surface water has been regulated by more stringent standard. The air stripping method is successfully used to treatment of high-concentration ammonia nitrogen; however, alkali will be added to keep pH more than 10, which is costly and not environment-friendly operation. In this study, an advanced air stripping (AAS) based on foam separation of removing ammonia nitrogen in low concentration from aqueous solution at low pH was proposed. The effect of conditions such as air flow rate, temperature, SDS dosage, coexisting ionic strength, pH, and initial ammonia nitrogen concentration on the removal efficiency was studied. The advanced air stripping exhibited favorable removal efficiency for NH 4 + -N in low concentration from aqueous solution (20 mg·L −1 ) with a broad range of low pH 3.0–9.0. Besides, for strongly alkaline (pH=11.0) solution, the advanced air stripping can alleviate the decrease of pH to some extent and keep ammonia nitrogen stripping out continuously based on equilibrium shift between NH 4 + and NH 3 . A microcalorimeter was applied to demonstrate the interaction between the negatively charged hydrophilic groups of SDS and NH 4 + ions, helping to understand the mechanisms more clearly. The simple operation and the satisfactory removal efficiency could imply that the advanced air stripping is a promising technology for minimizing low-concentration NH 4 + -N. Graphical abstract
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FOOD HYDROCOLLOIDS
·
2021
·
IF 9.147
Yizhou Xu,Jiulin Wu,Shaoyun Wang
To overcome hydrophobicity and chemical instability of resveratrol (Rev), modified whey protein isolate (WPI) and gelatin (Gel) were used to load Rev. Three treatments including pH-shifting at pH 12 (S), pH-shifting at pH 12 combined with ultrasonication at pH 7 (SU7), and pH-shifting at pH 12 combined with ultrasonication at pH 12 (SU12) were conducted to obtain a series of modified proteins (WPI-S, WPI-SU7, WPI-SU12, Gel-S, Gel-SU7, Gel-SU12). Among them, WPI-SU12 and Gel-SU12 had the highest encapsulation efficiency (EE) and loading capacity (LC) for Rev. The EE and LC were 92.69 ± 0.25% and 17.37 ± 0.067 g/100 g protein in WPI-SU12-Rev nanocomposite , respectively, and 83.85 ± 0.43% and 15.68 ± 0.070 g/100 g protein in Gel-SU12-Rev nanocomposite, respectively. This might be related to the highest surface hydrophobicity of modified proteins in SU12 groups. The particle sizes of all nanocomposites were below 200 nm, while the higher ζ-potential absolute value of WPI-SU12-Rev nanocomposite than that of Gel-SU12-Rev nanocomposite indicated higher stability. Molecular interaction and secondary structure analysis verified that the proteins and Rev bound to each other. Moreover, protein nanocomposites could greatly improve the water solubility and antioxidant capacity of Rev. In summary, the WPI modified by ultrasonication at pH 12 showed the best loading with Rev.
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2021
·
IF 8.198
Mengya Mu,Yingzhan Li,Hou-Yong Yu,Ziheng Li,Yiwen Cao,Xinyi Chen
Although chemical cross-linking could greatly improve the mechanical flexibility of nanocellulose aerogels, current cross-linking strategies still have some shortcomings, such as a complex cross-linking process or toxic cross-linking agents. Herein, a copolymer (PDMAEMA-co-PVTMS) containing polyorganosiloxane and a pH-responsive segment was designed and synthesized via free-radical polymerization. The polyorganosiloxane could covalently cross-link to a cellulose nanofiber (CNF) and the dimethylaminoethyl methacrylate (DMAEMA) section could endow the aerogel with pH-responsive properties. The prepared aerogel showed a three-dimensional (3D) porous structure with a specific surface area as high as 53.88 m2/g. Furthermore, the cross-linked aerogel had excellent mechanical flexibility and its maximum stress could be maintained above 71.3% of the initial value (11.88 kPa) after 50 cycles. More importantly, the aerogel could turn from a positive charge to a negative charge when the environment changed from acidity to alkalinity. It could be used to adsorb bovine serum albumin (BSA) in an acidic environment and adsorption capacity could reach 107 mg/g. It also could release 97% of adsorbed BSA in an alkaline environment. This work provided a new strategy to construct functional cellulose aerogels with excellent mechanical properties through structural design of a cross-linking agent containing organosiloxane.
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
·
2021
·
IF 5.268
Ning Wang,Chenyu Liu,Weihe Yao,Hengjun Zhou,Simiao Yu,Hailiang Chen,Weihong Qiao
Constructing highly efficient and multifunctional nanoparticles to overcome the multiple challenges of targeted drug delivery is a new strategy urgently needed in tumor therapy. Here, we synthesized pH-responsive prodrug ( PEG 2K -NH -N- DOX ), GSH-responsive prodrug ( PEG 2K -S-S-CPT ), folate-receptor targeting polymers ( FA-PEG 2K -L8 , FA-PEG 2K -TOS) and T1-enhanced magnetic resonance imaging contrast agents ( Gd-DTPA-N16−16) , used to encapsulate combrestatinA4 (CA4) to prepare multifunctional nanoparticles ( FTDCAG NPs). Unlike other nanoparticles, FTDCAG NPs contains three drugs with the ability to control the release in time and space, which can maximize the effectiveness of precise cancer chemotherapy. We first confirmed that specific binding between FTDCAG NPs and overexpressed folate-receptor cells by flow cytometry and confocal laser scanning microscopy. We then investigated the spatiotemporally controlled release ability of FTDCAG NPs loaded with doxorubicin (DOX), CA4 and camptothecin (CPT). Relative to pH = 7.4, the release efficiency of CA4 in the pH = 6.5 increased by 63.4 %. The first released CA4 is able to destroy the angiogenesis and help tumor cells to be exposed to the remaining FTDCG NPs. After being internalized into the tumor cells, FTDCG NPs is disassembled and the CPT and DOX were released due to the increase of intracellular GSH concentration and the decrease of pH value. Besides, the relaxation time of FTDCAG NPs is 3.86 times that of clinical Gd-DTPA, and the in vitro and vivo T1-weighted imaging is brighter, which can be used to trace the nanoparticles by MRI. Therefore, FTDCAG NPs provide an efficient strategy for the design of multifunctional drug delivery systems for enhancing antitumor efficacy.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Catalysis
·
2021
·
IF 13.084
Jiayi Qin,Cong Xi,Rui Zhang,Tao Liu,Peichao Zou,Deyao Wu,Qianjin Guo,Jing Mao,Huolin Xin,Jing Yang
It is highly desirable to develop all-pH-compatible hydrogen evolution reaction (HER) electrocatalysts that can be used universally in a variety of different electrolyzers and operated in different pH conditions, i.e., acid, alkaline, microbial, chlor-alkali, etc. So far, two-dimensional layered MoS2 and Mo-based carbon materials have been regarded as promising pH-universal HER electrocatalysts. 2H-MoS2 as a naturally occurring and thermodynamically favorable phase, yet still suffers from poor HER activity in neutral and alkaline electrolytes. Herein, a hybrid electrocatalyst, i.e., 2H-MoS2/N-doped mesoporous graphene, rich in interfacial Mo–pyridinic N coordination is fabricated. The optimized hybrid catalyst delivers long-term durability and outstanding HER activity with overpotentials of 110, 145, and 142 mV at 10 mA cm–2 in acidic, alkaline, and phosphate buffered solutions (PBS) media, respectively, outperforming most of the previously reported MoS2-based catalysts. Theoretical and experimental results demonstrate that the interfacial pyridinic N has a higher tendency to bond with Mo atoms than pyrrolic and graphitic N, and the edge-Mo coordinated with pyridinic N could serve as HER active sites. DFT calculations further reveal that Mo–pyridinic N coordination modifies the charge density of edge-Mo, in turn optimizing the hydrogen absorption energy and facilitating water dissociation, and thereby significantly promoting the intrinsic catalytic activity for the pH-universal HER process.
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2021
·
IF 8.198
Kemin Lv,Zhimeng Yu,Marcelo M. Pedroso,Bin Wu,Zhen Gao,Bingfang He,Gerhard Schenk
Establishing a suitable immobilization strategy to improve the accessibility of immobilized cellulase for insoluble cellulose and subsequently recover the enzyme from the remaining substrate is crucial to promote the industrialization of biofuels. Here, using iminodiacetic acid (IDA) and Ni2+ ions, a novel metal-chelated copolymer of methacrylic acid and methyl methacrylate was prepared for the immobilization of His-tagged processive endoglucanase EG5C-1 via affinity interaction between polyhistidine tag and Ni2+. The optimum loading capacity of the functionalized polymer (Eud-IDA-Ni2+) for EG5C-1 was about 280 mg/g, where more than 80% of the activity was recovered. Immobilized EG5C-1 exhibited improved thermal and pH stability and better reusability than the free one, and after five cycles of usage, the hydrolysis productivity remained above 70% of the initial value. The Eud-IDA-Ni2+/EG5C-1 biocomposite displayed reversibly soluble–insoluble characteristics with pH change, which was in the soluble state during the enzyme reaction process but could be recovered in an insoluble form by lowering the pH after the reaction. Thus, the yield obtained from the hydrolysis of an insoluble phosphoric acid-swollen cellulose substrate was similar for the free and immobilized form of EG5C-1. Our combined results suggested that a metal-ion-chelated, pH-responsive polymer had the potential for His-tagged cellulase immobilization to improve both the operational efficiency and economic benefit of the cellulosic biorefinery industry.
✓ 已验证
产品关联
DOI
高影响因子
TALANTA
·
2020
·
IF 5.339
Muhammad Mujahid Ali,Dilshad Hussain,Yan Tang,Xuechun Sun,Zhengchao Shen,Fengxia Zhang,Zhenxia Du
Boronic acid-based affinity materials have gained tremendous attention for the selective separation and recognition of cis-diol containing biomolecules. But often, these boronate affinity materials are stuck to some serious issues like high binding pH and weak affinity, especially in the case of glycoproteins . Here in this study, we used 5-boronoisophthlic acid as a novel affinity ligand for the selective capture and release of glycoproteins. The pKa value of 5-boronoisophthalic acid is investigated to be 7.8 which is just closed to physiological pH and is ideally suitable for the fast binding and elution kinetics of glycoproteins to avoid their degradation and deactivation. The affinity ligand is attached to the surface of polymer support using branched polyethyleneimine (PEI) which enhances the binding strength as it has multiple amine groups available for the attachment of 5-boronoisophthalic for synergistic interactions. The resulting affinity material is characterized and packed in a micropipette-tip using hydrophilic melamine foam as a frit to make the separation process smooth, simple, reliable, and robust. This boronic acid-based affinity tip exhibits binding constants for model glycoproteins in the range of 10 −6 –10 −7 M, binding capacities in the range of 0.662 μM/g, and selectivity up to 1:1000 (HRP to BSA) under optimized extraction conditions. Finally, the boronic-based affinity tip is successfully applied to selectively capture the glycoproteins from the human milk sample, especially lactoferrin which is highly important in dairy manufacture.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2020
·Vol. 187
·期 8
·1-9
·
IF 6.232
Xu Shaomei,He Xu,Huang Yibing,Liu Xin,Zhao Lihe,Wang Xinghua,Sun Ying,Ma Pinyi,Song Daqian
A hydrothermal method has been employed to synthesize a green and one-pot carbon dots-based sensor for ratiometric monitoring and imaging lysosomal pH in living cells. The carbon dots were directly functionalized by abundant amino groups during synthesis and exhibited dual emission bands at 439 and 550 nm under single-wavelength excitation of 380 nm without any additional modification. In addition to its small size, the established sensor had good biocompatibility. Owing to its abundant amino groups and good hydrophilicity, the sensor is able to target lysosome with high Pearson’s colocalization coefficients (0.935 and 0.924) and responds to change of lysosomal pH in living cells. It also had excellent pH sensitivity and reversibility, and anti-interference capability, thus enabling sensing pH change in intracellular environment in real time, as demonstrated by successful monitoring of lysosomal pH changes during lysosomal alkalization, dexamethasone-induced stimulation, and stress in Michigan Cancer Foundation-7 cells (blue channel, excitation = 405 nm and emission = 419–459 nm bandpass; and yellow channel, excitation = 405 nm and emission = 530–570 nm bandpass).
Graphical abstract
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）