查找使用阿拉丁产品的科研文献

A solid-contact pH-selective electrode based on tridodecylamine as hydrogen neutral ionophore

Jianxin Zhang,Yixuan Guo,Shangjin Li,Hui Xu

The solid-state pH electrode has the potential possibility to be used in many extreme situations with satisfactory accuracy and low cost. But its performance is affected by the solid electrolyte, preparation process, and the structure of the sensitive membrane, etc. In this work, the relationships between these factors and the characteristic of the prepared electrode were verified by controlling the preparation conditions with a variety of electrochemical methods. Firstly, the solid electrolyte poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS) was electrochemically deposited on the screen-printed carbon electrode (SPCE) substrate by a potentiostatic method in an aqueous solution containing 0.01 M 3,4-ethylenedioxythiophene (EDOT) and 0.1 M polystyrene sulfonic (PSS) acid as the supporting electrolyte. The PEDOT films were then characterized by cyclic voltammetry (CV) in the 0.1 M NaNO3 aqueous solution in order to obtain the optimized polymerization potential and charges where the PEDOT film would have a higher redox capacitance. Finally, the pH electrode was prepared by coating the SPCE/PEDOT(PSS) with a plasticized polyvinyl chloride (PVC) membrane containing tridodecylamine as hydrogen ionophore manually, and experiments were carried out to study the effect of the usage of PVC per square millimeter on the response time and stability of the electrode to optimize the PVC film thickness. The potentiometric response of the pH electrode was studied in the buffer solutions with pH ranging from 5.00 to 10.81 by the open-circuit potential (OCP) method. Experimental results show that the sensitivity of the electrode is  −55.7  ±  0.5 mV pH−1 (r2  >  0.9980) at room temperature (24  ±  1 °C) with pH ranging from 2.00–10.50, approximating to the theoretical nernstian slope (−59.16 mV pH−1),and the response time was less than 10 s. Moreover, it has low impedance, high accuracy and potential stability as well as some other useful properties such as pressure and heat resistance, hydrofluoric acid resistance, and it is not as fragile as the glass electrode.

Assessing the effects of cellulose-inorganic nanofillers on thermo/pH-dual responsive hydrogels

Yiying Yue,Huiming Luo,Jingquan Han,Yiliang Chen,Jianchun Jiang

The incorporation of renewable bio-based materials/eco-friendly inorganic nanofillers into stimuli-responsive hydrogels meets the need for biocompatible and non-toxic functional materials. However, it remains challenging to build a three-dimensional network with enhanced mechanical properties and desired stimuli-responsive performances. In this study, dual stimuli-responsive hydrogels with interpenetrating polymer network structure are fabricated by the crosslinking of N-isopropylacrylamide (NIPAM) 1 and sodium alginate (SA) 2 . 2,2,6,6-tetramethyl-piperidine-1-oxyl-oxidized cellulose nanofibers (TOCNF) 3 derived from energycane bagasse serves as a carrier material for nanosilicas (NS) 4 and nanoclays (NC) 5 and the effects of TOCNF , TOCNF/NS and TOCNF/NC on the hydrogels are thoroughly explored. Among these hydrogels, PNIPAM/SA-TOCNF-NS possesses the largest compressive strength of 66.7 kPa and it is 5.65 times higher than that of PNIPAM/SA. The thermo-sensitivity and pH-sensitivity of hydrogels are evidenced by swelling behaviors, optical properties, contact angle measurements and fluorescence tests. PNIPAM/SA-TOCNF exhibits the largest contact angle and the swelling processes for all the hydrogels are well fitted by pseudo-second-order swelling kinetic model. In addition, after incorporating carbon quantum dots, all the hydrogels display temperature dependent on–off fluorescence properties and this process are fully reversible with the heating and cooling cycles. These novel hydrogels with pH and temperature responsive characteristics and remarkable mechanical properties will open the door for interesting applications in smart sensors etc.

A pH-Sensitive, Stretchable, Antibacterial Artificial Tongue Based on MXene Cross-Linked Ionogel

Hui Zhi,Xiaobo Zhang,Fengya Wang,Liang Feng

Dehydration has always been a confusing problem for a hydrogel exposed to air, which restricts its application in practical detection. While an ionogel with unique properties can lock water molecules efficiently due to its low vapor pressure, the design and development of an ionogel with excellent water-locking properties and stability to achieve satisfactory detection are thus highly desirable. In this work, a pH-sensitive, stretchable, antibacterial, and stable ionogel artificial tongue was fabricated through dual cross-linking. The artificial tongue consisted of MXene as a cross-linking agent, phenol red as an indicator, gelatin, N-(2-hydroxyethyl) acrylamide, and 1-butyl-3-methylimidazolium chloride as the three-dimensional polymer network. A small quantity of MXene was used as a cross-linker the first time to promote the initiator in the system to generate free radicals, accelerating the reaction process and the multilevel linkage among the polymers. Meanwhile, the indicator phenol red was introduced into the ionogel successfully for the first time, showing great stability in 5 weeks. After evaluation by the Brand–Altman analysis, it was found that the method of pH measurement using ionogels had good consistency with the pH meter measurement method. Additionally, the prepared ionogel presented excellent water retention, mechanical stretchability, antibacterial property, and stability, as well as good test results in the test of artificial simulated saliva, demonstrating great potential in clinical applications.

Smartphone-Based Hand-Held Optical Fiber Fluorescence Sensor for On-Site pH Detection

Ting Liu,Wenqi Wang,He Ding,Dingrong Yi

An Optical Sensor with Polyaniline-Gold Hybrid Nanostructures for Monitoring pH in Saliva

Chongdai Luo,Yangyang Wang,Xuemeng Li,Xueqin Jiang,Panpan Gao,Kang Sun,Jianhua Zhou,Zhiguang Zhang,Qing Jiang

Saliva contains important personal physiological information that is related to some diseases, and it is a valuable source of biochemical information that can be collected rapidly, frequently, and without stress. In this article, we reported a new and simple localized surface plasmon resonance (LSPR) substrate composed of polyaniline (PANI)-gold hybrid nanostructures as an optical sensor for monitoring the pH of saliva samples. The overall appearance and topography of the substrates, the composition, and the wettability of the LSPR surfaces were characterized by optical and scanning electron microscope (SEM) images, infrared spectra, and contact angles measurement, respectively. The PANI-gold hybrid substrate readily responded to the pH. The response time was very short, which was 3.5 s when the pH switched from 2 to 7, and 4.5 s from 7 to 2. The changes of visible-near-infrared (NIR) spectra of this sensor upon varying pH in solution showed that—for the absorption at given wavelengths of 665 nm and 785 nm—the sensitivities were 0.0299 a.u./pH (a.u. = arbitrary unit) with a linear range of pH = 5–8 and 0.0234 a.u./pH with linear range of pH = 2–8, respectively. By using this new sensor, the pH of a real saliva sample was monitored and was consistent with the parallel measurements with a standard laboratory method. The results suggest that this novel LSPR sensor shows great potential in the field of mobile healthcare and home medical devices, and could also be modified by different sensitive materials to detect various molecules or ions in the future.

PH and redox dual-responsive polymeric micelles with charge conversion for paclitaxel delivery

Bo Li,Shigang Pang,Xinxin Li,Yanhai Li

Here we demonstrate a type of pH and redox dual-responsive micelles, which were self-assembled in aqueous solution by an amphiphilic polymer, methoxypoly(ethylene glycol)-cystamine-poly(L-glutamic acid)-imidazole (mPEG-SS-PGA-IM). Considering tumor cells or tissues exhibiting low pH values and high glutathione (GSH) concentration, mPEG-SS-PGA-IM micelles possessed the charge conversion at pH of tumor tissues, which can facilitate cellular uptake of tumor cells. Furthermore, mPEG-SS-PGA-IM micelles can escape from endo/lysosomes based on the proton sponge effect, following degraded by higher concentration of GSH in cytoplasm. CLSM images of HCT116 cells indicated that mPEG-SS-PGA-IM micelles can escape from endo/lysosomes and enter cytoplasm. MTT assay showed that (paclitaxel) PTX-loaded mPEG-SS-PGA-IM micelles had higher cytotoxicity against HCT116 cells compared with PTX-loaded mPEG-PBLG and mPEG-SS-PBLG micelles. These results indicated that these mPEG-SS-PGA-IM micelles, as novel and effective pH- and redox-responsive nanocarriers, have great potential to both improve drug targeting efficiency while also enhancing the antitumor efficacy of PTX.

Mussel-Inspired pH-Switched Assembly of Capsules with an Ultrathin and Robust Nanoshell

Ziyi Cai,Jiafu Shi,Weiran Li,Yizhou Wu,Yishan Zhang,Shaohua Zhang,Zhongyi Jiang

Enclosed films, also called capsules, bearing an ultrathin and robust nanoshell have sparked much interest for use in many applications, for which facile preparation methods are urgently pursued. Inspired by the pH-programmed adhesion/cohesion of mussel-secreted foot proteins, polyphenol/polyamine capsules with an ultrathin and robust nanoshell are fabricated through a pH-switched assembly on sacrificial calcium carbonate (CaCO3) templates. Polyphenols adhere to the templates at pH 6.0 and rapidly cohere with polyamines at pH 8.0. The pH-switched assembly process is accomplished in only a few minutes where multiple instances of electrostatic interactions and chemical conjugation between polyphenols and polyamines occur. As a result, the capsules exhibit a nanoshell thickness of ∼10 nm and a superior mechanical strength of ∼1.575 GPa (elasticity modulus). Cell mimics are prepared through encasing enzymes in the lumen and present an activity recovery of ∼70% along with little activity decline during reuse. Amine or phenolic groups on the nanoshell of capsules are then applied to induce the generation of titania or silver nanoparticles, which may expand the applications of the capsules to the photo- and biorelated realms. Our study not only deepens the understanding of the adhering process of mussels but also offers a generic method toward functional materials for diverse applications.

One-step preparation of durable pH-responsive polyurethane foam for oil/water separation

Feifei Shao,Tao Xue,Yijing Wang,Yesheng Xu,Xinjie Wang,Xinxin Li

The smart responsive materials have become one of the hottest areas of research in oil/water separation field and there are various studies on preparation technologies. However, most of the materials reported were prepared by coating or coupling to attach functional polymer to substrates, which generally had unstable physical and chemical properties and were difficult to be applied in harsh environments. In this work, we fabricated a smart and durable oil/water separation material by one-step foaming method to graft pH-responsive copolymer onto a polyurethane foam (PUF) substrate. The foam exhibited reversible wettability under different pH environments, had excellent oil adsorption capacity (24.78–64.27g/g) and high oil/water separation efficiency (above 98%). Besides, the foam also showed stable performance and excellent recyclability in a series of durability experiments, including mechanical abrasion, light radiation and chemical immersion. The foam with simple preparation process and excellent stability will have promising application prospects in the field of oil/water separation.

pH and temperature responsive porous membranes via an in situ bulk copolymerization approach

Runnan Zhang,Yanlei Su,Jinming Peng,Xiaochen Fan,Zhongyi Jiang,Xueting Zhao,Jiazhen Liu,Yafei Li,Jiaojiao Zhao

In the present study, an in situ approach to pH and temperature responsive membranes is developed. The membrane matrix is formed through bulk polymerization and crosslinking of liquid monomer 2-hydroxyethyl methacrylate (HEMA) while the membrane pores are formed by the templating of inorganic particles . The functional monomers methacrylic acid (MAA) and N-isopropylacrylamide (NIPAAm) are incorporated into membrane casting solution in order to confer membranes with pH and temperature responsive properties. The poly(HEMA/MAA) membranes exhibit a reversible pH-dependent water flux, while the poly(HEMA/NIPAAm) membranes exhibit a reversible temperature-dependent water flux. The flux of the poly(HEMA/MAA) membrane increased by 70% when pH was decreased from 10.0 to 2.0, while the flux poly(HEMA/NIPAAm) membrane increased by 150% when temperature was increased from 20 to 45 °C. The protein adsorption and antifouling performance of the poly(HEMA/MAA) and poly(HEMA/NIPAAm) membranes also exhibit pH and temperature responsive properties.

A pH-responsive and nitric oxide-producing nanocarrier for targeted therapy of melanoma

Shuai Cui,Qing Yu,Ziyuan Su,Yiting Han,Sujuan Wang,Xiangyu Zou,Lin An,Nannan Yin,Hao Hong,Dongzhi Yang

In this study, we developed and characterized L-A@HMSN-Pt@MPN, a pH-responsive controlled-release nanocarrier for targeted nitric oxide (NO) delivery to cancer cells. Leveraging the abundant hydrogen peroxide (H 2 O 2 ) within tumor cells, platinum nanoparticles (Pt NPs) catalytically generated oxygen (O 2 ), facilitating the conversion of L-arginine (L-Arg) to NO. The metal-phenol network (MPN) acted as a pH-responsive switch, controlling L-Arg release from hollow mesoporous silica nanospheres (HMSNs). We characterized the structural and functional properties of the nanocarrier, evaluated the NO generation capacity, and assessed its effects on cancer cells in vitro and in vivo . Results demonstrated that L-A@HMSN-Pt@MPN exhibited significant tumor-selective cytotoxicity with minimal impact on normal cells. Critically, it induced cancer cell apoptosis through NO and reactive oxygen species (ROS) production. In vivo studies confirmed its therapeutic efficacy and revealed no significant biosafety concerns. This study proposes a strategy for NO delivery, potentially facilitating further research in gas-mediated cancer therapy.

Self-healable, Temperature-Sensitive, pH-Sensitive Ti3C2TX MXene Hydrogel as an Epidermal Sensor

Yang Xiaoli,Zhang Xiaomin,Zhang Han,Cong Yuhan,Wang Zitan,Ye Erkang

MXene-based hydrogels have become important materials for epidermal applications due to their excellent conductive properties and biocompatibility. Nonetheless, the application of such materials in the epidermal field is limited because of insufficient mechanical properties, unidimensional stimulus response, and complex preparation methods. In this study, an MXene-based hydrogel with outstanding self-healing, temperature sensitivity, and pH sensitivity was prepared by a one-pot method at 60°C for 5 h. The hydrogel is composed of Ti 3 C 2 T x MXene nano-slices, polyacrylamide (PAM), poly( N -isopropylacrylamide) (PNIPA), and polyacrylic acid (PAA), denoted as MXene/PAM/PNIPA/PAA hydrogel (MPANA hydrogel). The MPANA hydrogel exhibits excellent mechanical properties. Its tensile strength, elastic modulus, toughness, and elongation at break are 2.79 MPa, 0.64 MPa, and 51 MJ/m 3 , 412%, respectively, which indicates that the hydrogel possesses good stretchability. Moreover, the MPANA hydrogel demonstrates good self-healing ability, attaining an average strain self-healing efficiency of 94%, achieved in 12 h. Additionally, the MPANA hydrogel shows impressive thermal response sensitivity (−1.3560% °C −1 ) and a rapid pH response time (32–53 s). In conclusion, the MPANA hydrogel has significant potential for applications in epidermal sensors. Graphical

A pH-Resilient fluorogenic probe for stable high-resolution imaging of lysosomal dynamics

Xiangning Fang,Guanyu Jiang,Qinglong Qiao,Xiaogang Liu,Zhaochao Xu

Rhodamines are widely utilized for fluorescence switching, biosensing, and super-resolution imaging due to their dynamic equilibrium between a non-fluorescent "closed" spiro-ring form and a fluorescent "open" xanthylium form. This equilibrium has inspired extensive efforts to chemically modulate their spiro-ring behavior. In this study, we uncover a novel mechanism in aniline-rhodamine ( PR ), where the interplay of NH protonation, deprotonation, and hydrogen bonding collaboratively governs spirolactone ring opening. Notably, this interplay stabilizes the ring equilibrium in aqueous solutions within the pH range of 4–10, minimizing sensitivity to pH fluctuations. Leveraging this mechanism, we designed an aniline-rhodamine derivative, EPR , which maintains stable fluorescence regardless of lysosomal pH variations. This stability enables consistent, high-resolution imaging of lysosomal dynamics under both physiological and pathological conditions, offering deep insights into lysosomal functions within cellular regulatory networks. The NH groups in PR establish a new regulatory axis for rhodamine ring switching, providing a promising foundation for developing next-generation fluorescent probes with enhanced stability and functionality.