ANALYTICAL CHEMISTRY
·
2021
·
IF 6.986
Hui Dong,Le Zhao,Yanli Zhou,Xiuhua Wei,Cuicui Xu,Yintang Zhang,Maotian Xu
Brain pH has been proven to be a key factor in maintaining normal brain function. The relationship between local pH fluctuation and brain disease has not been extensively studied due to lack of the accurate in situ analysis technology. Herein, we have for the first time proposed a voltammetric pH sensor by measuring the ratio of current signals instead of the previously reported potential based on the Nernst equation. Single-walled carbon nanotubes (CNT) were first self-assembled on the electrode surface of a carbon-fiber nanotip electrode (CFNE). Then, poly-o-phenylenediamine (PoPD) molecules were deposited as pH-responsive molecules through in situ electrochemical polymerization. The compact CFNE/CNT/PoPD exhibited a good redox process with the on–off–on ratiometric electrochemical response to pH ranging from 4.5 to 8.2, providing self-correction for in situ pH detection. Thus, the proposed sensor enabled the accurate measurement of pH with excellent selectivity even in the presence of proteins or electroactive species. In addition, the sensor showed high repeatability, reproducibility, and reversibility in measuring pH and even demonstrated good stability when it was exposed to air for 5 months. Finally, we successfully detected the fluctuation of pH in rat brains with cerebral ischemia and rat whole blood. Overall, this research not only provides a good tool for the detection of rat brain pH but also provides a new strategy for further designing nanosensors for intracellular or subcellular pH.
研究领域:
神经科学
·
生物医学工程
·
分析化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2024
·
IF 4.1
Yu-Hua Xiao,Qiu-Yu Huang,Jian Wang,Xin-Ran Li,Ze-Jie Zhu,Qin-Hao Zhang,Fa-He Cao
Localized and interface pH values are important parameters for studying the corrosion progress and complex interface reactions. Although commercial glass pH sensors have been widely used to measure solution pH value due to their advantages of long stability and high sensitivity, they were unable to determine the interface and microregion pH value for their difficulty in miniaturization. In this work, an all-solid-state pH micro-sensor with strong adhesion strength was in-situ fabricated on diameter 15 μm tungsten ultramicroelectrode (UME) using constant current anodizing. The pH micro-sensor showed good linear response (R 2 = 0.999), excellent sensitivity (with a slope of −53.8 mV/pH), quick response (<0.1 s), long lifetime (>44 days) and great anti-interference ability to most of the ions in marine (selectivity coefficients pK ij > 7), such as SO 4 2− , Cl − , NO 3 − , K + , Mg 2+ and Fe 2+ . Then, the pH micro-sensor, combined with the potentiometric mode of SECM, was further employed to explore the localized pH value distribution during the galvanic corrosion of Fe-Cu couple in 0.1 M NaCl solution. To further verify the anti-interference ability of pH micro-sensor, potentiometric SECM experiment was also conducted in artificial seawater. Results showed that both acidic sites and alkalizing sites appeared on the Fe surface, while homogeneous alkalization took place overall Cu surface. This was consistent with the SVET results that anodic and cathodic areas existed simultaneously on Fe surface. Thus, it could be concluded that local corrosion occurred on Fe surface and only part of the Fe surface acted as the anodic even under galvanic effect. However, Cu acted as cathode with the homogeneously distributing cathodic current on the whole surface during the galvanic corrosion.
研究领域:
材料科学
·
电化学
·
腐蚀科学
·
传感器与执行器
·
环境监测
✓ 已验证
产品关联
DOI
高影响因子
NANOTECHNOLOGY
·
2022
·Vol. 33
·期 26
·265002
·
IF 3.953
Xiaohui Fan,Yang Wang,Bo Li,Chang Shen,Zhengguang Sun,Yuan Zhan,Yuhong Zhang
Carbon quantum dots (CDs) have attracted tremendous interest owing to their idiosyncratic functions and wide-ranging applications. However, it remains a great challenge to empolder an integrated CDs combining high luminescence, biocompatibility and luminescence color tunability for bioimaging via simple approach. In this work, pH-responsive carbon quantum dots (Si-CDs) with high luminescence (quantum yield = 74.8%) were fabricated by one-step hydrothermal method using (3-mercaptopropyl) triethoxysilane (KH-580) as modifier for the first time. The optical properties of the as-prepared Si-CDs can be controlled from obvious green–blue–violet transformation by altering the pH. More importantly, the change is reversible and repeatable. In addition, the Si-CDs have good biocompatibility and chemically inert in vitro cell system simulation. Such non-toxic, environmental friendly, low-cost, inert CDs materials are promising candidates for biomedical and pH-sensitive sensors.
研究领域:
生物医学
·
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Frontiers in Chemistry
·
2020
·
IF 3.693
Ai Qiushuang,Fu Qiang,Liang Feng
Recognition tunneling technique owns the capability for investigating and characterizing molecules at single molecule level. Here, we investigated the conductance value of cucurbit[7]uril (CB[7]) and melphalan@CB[7] (Mel@CB[7]) complex molecular junctions by using recognition tunneling technique. The conductances of CB[7] and Mel@CB[7] with different pH values were studied in aqueous media as well as organic solvent. Both pH value and guest molecule have an impact on the conductance of CB[7] molecular junction. The conductances of CB[7] and Mel@CB[7] both showed slightly difference on the conductance under different measurement systems. This work extends the molecular conductance measurement to aqueous media and provides new insights of pH-responsive host-guest system for single molecule detection through electrical measurements.
研究领域:
生物物理学
·
纳米科学
·
分子电子学
✓ 已验证
DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
·
2018
·
IF 5.158
Kaiqiang Zhang,Yulin Shi,Liang Wu,Long Chen,Tingting Wei,Xin Jia,Zhang Chen,Manqiu Li,Yisheng Xu,Yu Wang,Yanfeng Gao,Xuhong Guo
A thermo and pH dual-responsive starch (TPDS) was successfully synthesized by etherification, in which butyl glycidyl ether (BGE) was used as the hydrophobic reagent followed by addition of 2-chloro-4, 6-diglycino-[1,3,5]-triazine (CDT) groups. The obtained materials were characterized by Fourier transform–infrared spectroscopy (FTIR), 1 H nuclear magnetic resonance ( 1 H NMR) and elemental analysis to confirm the structure and the average substitution degree of BGE and CDT on starch molecule. It was observed that the lower critical solution temperature (LCST) of the TPDS could be modulated from 31 °C to 47 °C by increasing pH of the solution. The effects of pH and the concentration of such materials on the energy-saving performance of TPDS which could be potentially used as smart windows were investigated by UV-vis-NIR spectrophotometry. The solar modulating ability (△T sol ) and the luminous transmittance (△T lum ) of the sample were 40.1% and 47.1% when 10 g/L TPDS was chosen at pH 3. The results indicate that TPDS exhibits excellent optical performance with a controllable LCST, which shows great potential for the application as a smart window.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
·
2019
·
IF 3.973
Pengcheng Liu,Qiong Wu,Yanmei Li,Pengfei Li,Jiang Yuan,Xianwei Meng,Yinghong Xiao
Keratin is a good candidate for drug carrier due to its good biocompatibility, low immunogenicity, redox responsiveness, and abundant renewable sources. Herein, doxorubicin (DOX) was first conjugated with keratin through a pH-sensitive hydrazone linkage, and then prepared into particulate drug carrier via desolvation method. The size, morphology, and surface potential of keratin-DOX nanoparticles (KDNPs) were characterized by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The drug release results showed that KDNPs performed an excellent pH-sensitive behavior under acidic tumor microenvironment. Cytotoxicity assay by MTT confirmed that KDNPs exhibited the enhanced cytotoxicity against A549 cells. Furthermore, KDNPs had higher therapeutic efficiency in vivo than free DOX . Hemolysis assay indicated that KDNPs was blood compatible. All the results identified that KDNPs are well suited as an ideal drug carrier.
研究领域:
药剂学
·
生物材料
·
肿瘤学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
·
2014
·
IF 4.287
Fang Yuan,Shasha Wang,Gaojian Chen,Kehua Tu,Hongliang Jiang,Li-Qun Wang
A novel approach to design pH-sensitive and disintegrable polyelectrolyte nanogels composed of citraconic-based N -(carboxyacyl) chitosan (polyanion) and quaternary chitosan (polycation) was reported. Firstly, the hydrolysis of citraconic-modified chitosan was monitored using fluorescamine assay and it could selectively dissociate in acidic media (e.g., pH ∼5.0) due to the isomerization during the addition of citraconic anhydride to chitosan. Secondly, the self-assembly behaviors of different polyelectrolyte pairs between citraconic-based chitosan and quaternary chitosan were investigated via colloidal titration assay. It was indicated that the difference in molecular weight (MW) of opposite charged polyelectrolytes played an important role on the formation of polyelectrolyte nanogels. Results showed that polyelectrolyte nanogels (ca. 300 nm in size) only formed when polyanion and polycation had a very large difference in MW. The pH-sensitive behavior of polyelectrolyte nanogels was comprehensively investigated by dynamic light scattering (DLS) and transmission electron microscope (TEM). The incorporation of charge-conversional citraconic-based chitosan into polyelectrolyte complexes has provided an effective approach to prepare polyelectrolyte nanogels which were very stable at neutral pH but disintegrated quickly in acidic media.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL PAPERS
·
2019
·Vol. 74
·期 6
·1831-1838
·
IF 1.246
Cai Zhifeng,Zhang Caifeng,Jia Kang
A fast, simple, green and low-cost synthesis method in aqueous solution was successfully established for the preparation of l -tyrosine protected Cu nanoclusters (Cu NCs). Subsequently, the as-prepared Cu NCs was characterized by UV–vis absorption spectroscopy, fluorescence spectroscopy, transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). It exhibited good water solubility, excellent photostability and high stability toward high concentration of sodium chloride. The Cu NCs revealed maximum excitation and emission peaks at 430 and 477 nm, respectively. Importantly, the Cu NCs showed a rapid response, a liner relation over the pH ranges from 5.02 to 11.92 and could be repeated for five consecutive cycles without fluorescence decay. Further, the as-prepared Cu NCs was applied for the determination of pH value in water samples. Simultaneously, all above features showed that l -tyrosine protected Cu NCs had great potential for sensing of pH in biological field.
研究领域:
生物化学
·
材料科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Siyu Yang,Qiuyan Luo,Chuanluan Guo,Jia Jiang,Xiaohong Wang,Juguo Dai,Dongxu Li,Kaibin He,Yiting Xu,Conghui Yuan,Weiang Luo,Lizong Dai
Hydrogels have attracted widespread attention in anticounterfeiting due to their unique physical/chemical properties and designability. However, hydrogels’ poor mechanical properties and sluggish response to chemical stimuli pose challenges for their wide application. A fluorescent tough organohydrogel capable of freeform writing of information is reported in this work. By incorporation of the fluorescent monomer 7-methylacryloxy-4-methylcoumarin into the polyacrylamide network in a covalently cross-linked manner while intertwining with the carboxymethyl cellulose sodium network, a fluorescent tough organohydrogel with a dual-network structure is prepared. The organohydrogel shows acid–base-mediated adjustable fluorescence through the transformation of fluorescent monomers. Ion printing and electrical stimulation design achieved free information storage and encryption. In addition, the prepared organohydrogel has good antifreezing properties and can be encrypted and decrypted at subzero temperatures. The encrypted information in the organohydrogel can be read only after UV-light irradiation. These patterned fluorescent organohydrogels should find applications in protected message displays for improved information security.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Small
·
2015
·Vol. 11
·期 21
·2543-2554
·
IF 8.368
Shi-Song Han,Ze-Yong Li,Jing-Yi Zhu,Kai Han,Zheng-Yang Zeng,Wei Hong,Wen-Xin Li,Hui-Zhen Jia,Yun Liu,Ren-Xi Zhuo,Xian-Zheng Zhang
A novel dual-pH sensitive charge-reversal strategy is designed to deliver antitumor drugs targeting to tumor cells and to further promote the nuclei internalization by a stepwise response to the mildly acidic extracellular pH (≈6.5) of a tumor and endo/lysosome pH (≈5.0). Poly( l -lysine)- block –poly( l -leucine) diblock copolymer is synthesized and the lysine amino residues are amidated by 2,3-dimethylmaleic anhydride to form β-carboxylic amide, making the polypeptides self-assemble into negatively charged micelles. The amide can be hydrolyzed when exposed to the mildly acidic tumor extracellular environment, which makes the micelles switch to positively charged and they are then readily internalized by tumor cells. A nuclear targeting Tat peptide is further conjugated to the polypeptide via a click reaction. The Tat is amidated by succinyl chloride to mask its positive charge and cell-penetrating function and thus to inhibit nonspecific cellular uptake. After the nanoparticles are internalized into the more acidic intracellular endo/lysosomes, the Tat succinyl amide is hydrolyzed to reactivate the Tat nuclear targeting function, promoting nanoparticle delivery into cell nuclei. This polypeptide nanocarrier facilitates tumor targeting and nuclear delivery simultaneously by simply modifying the lysine amino residues of polylysine and Tat into two different pH-sensitive β-carboxylic amides.
研究领域:
药学
·
纳米技术
·
癌症治疗
·
药物递送系统
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2025
·
IF 2.7
Zhongrui Wang,Yuwen Meng,Nan Sun,Yongzheng Xing,Xu Wang
This study introduces a novel design for pH-sensitive bilayer Janus hydrogels with bidirectional bending capabilities, achieved through the layer-by-layer polymerization of two distinct hydrogel layers. The upper layer, composed of P(HEMA -co- 4VP), swells in acidic environments due to the protonation of pyridine groups, inducing bending toward one side. Conversely, the lower layer, made of P(HEMA -co- AA), expands in alkaline conditions by deprotonation, causing bending toward the opposite direction. The bilayer hydrogel demonstrates significant shape deformations, influenced by variations in layer thickness and pH conditions. Detailed analyses of swelling behaviors, compressive toughness, and rheological properties reveal that the unique composition ensures distinct and tunable mechanical responses. Furthermore, hydrogels fabricated into complex geometries, such as flower- and starfish-shaped structures, showcase practical applications in soft robotics and biomimetic devices. The versatility of the design is further confirmed by substituting P(HEMA -co- 4VP) with P(HEMA -co- DMAEMA), which maintained the bidirectional bending responses under both acidic and alkaline conditions. This research expands the theoretical understanding of stimulus-responsive hydrogels and offers an innovative platform for designing intelligent actuators adaptable to diverse and dynamic environments.
研究领域:
材料科学
·
软体机器人
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2021
·
IF 8.742
Qingqing Guo,Xin Wu,Yanhong Ji,Yufan Hao,Shuyu Liao,Zhenyu Cui,Jianxin Li,Mohammad Younas,Benqiao He
Nanofiltration (NF) membranes with adjustable permeability and selectivity are highly desired for the separation of small molecules. A novel pH-responsive NF membrane was synthesized via interfacial polymerization with a mixture of piperazine (PIP) and chitosan (CS) as the aqueous phase and trimesoyl chloride (TMC) in n-hexane as the organic phase. The effects of pH on the physicochemical structure and performance of the PIP-CS/TMC NF membrane obtained were studied in detail. The results showed that the surface physicochemical structure and performance of the membrane could be changed by adjusting the pH of feed solution. Specifically, the surface roughness, hydrophilicity and pore size of the NF membrane were increased at high pH values. The pure water flux through the NF membrane remained stable in the pH range 2–8 but increased exponentially from 248.2 to 643.8 L m −2 ·h −1 as the pH was increased from 8 to 12. Furthermore, the PIP-CS/TMC NF membrane demonstrated more than 99.0% rejection for Congo red, methyl blue, coomassie brilliant blue G250 in the pH range 2–12, while low rejection was observed for methyl orange and inorganic salts (Na 2 SO 4 , MgCl 2 ) at pH 12. The NF membrane exhibited excellent separation performance of the mixtures of anionic dye/salt or dye/dye with different molecular weights at pH 12. The reversibility of pH response with a high responsive coefficient of the NF membrane was also proved. This work provides a new route for NF membrane in the separation of some dye/salt and mixed dyes systems.
研究领域:
材料科学
·
环境工程
✓ 已验证
DOI
高影响因子
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