Voltammetric Sensing of Trace Metals at a Poly(pyrrole‐malonic acid) Film Modified Carbon Electrode

The oxidative electropolymerization of the (3‐pyrrol‐1‐ylpropyl)malonic acid monomer 1 is a simple and reproducible one‐step procedure for the synthesis of complexing polymer film modified electrodes, which have been applied to the electroanalysis of Cu(II), Pb(II), Cd(II) and Hg(II) ions by preconcentration upon complexation, followed by anodic stripping analysis. The detection limits were determined from square‐wave voltammetry at 0.5 nM, 5 nM, 50 nM and 0.2 μM for Pb(II), Cu(II), Hg(II) and Cd(II), respectively, after 10 min preconcentration. The modified electrodes showed a better selectivity toward copper(II) ions. Analysis of copper in a tap water sample agreed well with ICPMS analysis results.     

Voltammetric Sensing of Mercury and Copper Cations at Poly(EDTA‐like) Film Modified Electrode

Complexing polymer‐coated electrodes have been synthesized by oxidative electropolymerization of ethylenediamine tetra‐N‐(3‐pyrrole‐1‐yl)propylacetamide (monomer L ). The presence of four polymerizable pyrrole fragments on the same EDTA skeleton was thought to confer enhanced rigidity and controlled dimensionality to the resulting complexing materials, which were used for the electrochemical detection of Hg(II), Cu(II), Pb(II) and Cd(II) ions by means of the chemical preconcentration‐anodic stripping technique. The polyamide electrode material showed particularly a significant selectivity towards mercury ions, even in the presence of a large excess of other metal cations. Moreover, the use of imprinted polymer‐coated electrodes prepared by electropolymerization of L in the presence of metal cations turned out to significantly improve the detection limits, down to 5×10^?10 mol L^?1 for Hg(II) and Cu(II) species.     

2D Material Chemistry: Graphdiyne-based Biochemical Sensing

The modern internet-of-things era has witnessed an increasing growth in the demand for advanced sensors to collect precise information. To meet this demand, extensive efforts have been devoted to exploring competent materials and designing rational architectures for the fabrication of sensing devices. Graphdiyne represents a promising material due to the attractive electronic, optical and electrochemical properties deriving from its unique molecular structure. In this review, we firstly provide the points of view on the architectures and work principles of the graphdiyne-based sensing devices with respect to resistive, electrochemical, photoelectrochemical and fluorescent categories. Secondly, we present the promising applications on biochemical sensing, such as the detection of DNA, microRNA, and glucose. Finally, the challenges and prospects of graphdiyne-based biochemical sensing platforms are also discussed, in order to provide a cornerstone for understanding this rapidly developing area.     

Novel Nickel Redox Polymer as an Efficient Electrode Material for Electrochemical Sensing

A novel redox polymer comprised of poly(3,4‐ethylenedioxythiophene) (PEDOT) and ethylenediamine tetraacetic acid‐Ni²⁺ (EDTA‐Ni) complex serving as doping anions has been synthesised by a facile one‐step electrochemical approach and utilized as an efficient electrode material for sensitive luteolin detection. The morphology, chemical structure and composition of the redox polymer were analyzed by SEM, UV‐vis and FT‐IR spectrum. Electrochemical tests revealed that the redox polymer was highly electrochemically reversible and exhibited good electrocatalytic activity to the redox reactions of luteolin with a linear range covering from 1 nM to 10 µM with a low detection limit of 0.3 nM of luteolin.     

2D Accordion-like MXene Nanosheets as a Sensitive Electrode Material for Baicalin Sensing

Herein, accordion-like MXene nanosheets was used as electrode sensing material for baicalin determination in traditional Chinese medicine preparation for the first time. The consecutive multilayer nanostructure of MXene observably enhanced the electroactive surface area of electrode and accelerated the electron transfer rate to acquire outstanding electrochemical response to baicalin. The electrode process of baicalin and relative dynamic parameters were investigated using cyclic voltammetry and chronocoulometry. Under optimized conditions, a good linear relationship was achieved between the response current and baicalin levels over the range of 0.08–60 μM with a detection limit of 26 nM (S/N=3). The developed sensor was successfully applied for baicalin monitoring in traditional Chinese medicine preparation and human urine samples.     

硫脲类阴离子受体的研究进展

阴离子识别是超分子化学研究的重要内容之一,其关键环节是构筑可识别阴离子的结合受体,后者以非共价键力如静电作用、疏水作用、氢键等与阴离子结合.本文详细评述了近5年来硫脲类阴离子识别受体的设计、结构及其阴离子识别作用的研究进展.     

掺杂聚丙炔醇及其酯的湿敏特性

聚醋酸丙炔酯;湿敏性;掺杂聚丙炔醇及其酯的湿敏特性     

Ferrocene derivatives supported on poly(N-vinylpyrrolidin-2-one) (PVP): Synthesis of new water-soluble electrochemically active probes for biomolecules

Carboxy-terminated polyvinylpyrrolidin-2-one (PVP) has been used as a new water-soluble and biocompatible polymeric support for a series of ferrocene labeled amino acid and peptide nucleic acid (PNA) monomer derivatives 4-7. The organometallic polymer-conjugates thus obtained are new and potentially useful as water-soluble electrochemically active probes for biomolecules. In view of such application, their electrochemical activity has been evaluated and has proved very high notwithstanding the complexity and bulkiness of the molecule, affording detection limits down to 10⁻⁸ M in the aqueous medium.     

Electrochemical Biosensing of DNA Immobilized Poly(Vinylferrocenium) Modified Electrode

The polymer, poly(vinylferrocenium) (PVF⁺) modified electrode was developed as the first time herein for the improved electrochemical sensing of DNA based on the oxidation signals of polymer and guanine. The morphologies of polymer film and DNA immobilized polymer film were examined using scanning electron microscope (SEM). The electrochemical behavior of polymer modified electrode was investigated by using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) in the absence/presence of DNA. Experimental parameters, such as the polymeric film thickness, the DNA immobilization time, the concentration of buffer solution, pH and DNA concentration were examined in order to obtain more sensitive and selective electrochemical signals. After optimization studies, DNA hybridization was also investigated.     

Electrochemical Recognition of Chiral Molecules with Poly(4‐bromoaniline) Modified Gold Electrode

A poly(4‐bromoaniline) (PBA) film is electrochemically synthesized on a gold electrode for the recognition of amino acids enantiomers. Scanning electron microscopy measurements show that the porous PBA films are made up of nano‐ribbons. At the PBA modified Au electrode differential pulse voltammograms of L ‐ and D ‐glutamic acids not only have very different current densities, but also produce different waveforms, providing an intuitive way to differentiate the two chiral molecules. Similar results are obtained in analyzing L ‐ and D ‐aspartic acids. Control experiments suggest that the observed sensing behavior arises from synergistic interactions between Au and the PBA film, where polymerization at the meta‐position creates a steric structure needed for differentiating chiral molecules.     

Electrochemical Sensing of Ascorbic Acid,Hydrogen Peroxide and Glucose by Bimetallic (Fe,Ni)−CNTs Composite Modified Electrode

In this research, bimetallic supported CNT modified electrode ( Fe,Ni/CNTs/GCE) has been developed for sensitive, stable and highly elctroactive sensing of glucose, ascorbic acid and hydrogen peroxide. Transition metals such as Iron (Fe) and Nickel (Ni) offer high electrical and thermal conductance, high active surface‐to‐volume ratio and presence of d‐band electrons gives enhanced electrocatalytic behavior. While, CNTs provide high surface area, stability and excellent conductivity. Synthesized material is characterized by SEM, EDS, XRD and FTIR to access morphology, elemental composition and structure. This unique combination is employed for the electrochemical sensing of ascorbic acid, glucose and hydrogen peroxide and different experimental parameters are optimized. Fe,Ni/CNTs/GCE shows good sensing efficiency at pH 7.4 which is ideally suitable for variety of analytes. The modified electrode also show good reproducibility and sensitivity under optimized conditions and can be reused upto 30 cycles without compromising the efficiency. With good linearity, reproducibility and limit of detection, this material possess significant potential as non‐enzymatic biosensor for variety of analytes.     

Metal‐Organic Frameworks (MOFs) as Functional Supramolecular Architectures for Anion Recognition and Sensing

Metal‐organic frameworks (MOFs) have experienced a tremendous growth during last few decades as porous crystalline molecular materials. The comprehensive effect of structural diversity, tunability and high surface area makes MOFs suitable for multifarious applications. MOFs can act as potential receptors toward different target components along with ionic species, small molecules, solvents, explosives etc. Anion recognition remains an important phenomena due to its involvement in many chemical and biological processes. Ligand designing, incorporation of appropriate functional groups and post‐synthetic modifications are key strategies in MOFs for selective recognition and scavenging of environmentally toxic and detrimental anions (i. e. cyanide, oxo‐anions etc.). The main focus of this personal account is on our research towards development and potential applications of MOFs with special emphasis on selective and sensitive anion sensing.     

Ferrocene Tethered Polyvinyl Alcohol/Silica Film Electrode for Electrocatalytic Sulfite Sensing

Ferrocene was linked to polyvinyl alcohol polymer via ethylene dioxi‐bis‐ethylamine (PV‐Fc) spacer and the synthesized redox polymer was characterised by FT‐IR and H¹NMR spectroscopy. Aqueous solution of PVA‐Fc was used to prepare its silica composite with tetraethylorthosilicate (TEOS). The immobilized PVA‐Fc/silica film showed E⁰ about 0.245 V and apparent diffusion coefficient was measured to be 2.76×10⁻⁸ cm² s⁻¹. The ferrocene with flexible spacer in PVA‐Fc/silica film showed an excellent electrocatalytic activity towards the sulfite oxidation at 0.35 V, that was minimum 0.3 V negative shift of the overpotential than the bare electrode. The effect of the interfearing species like acetate, ammonium, carbonate, phosphate and sulfate has been checked for the sulfite detection. Under the optimized conditions the prepared composite showed sulfite oxidation in the linear range of 5×10⁻⁷ M to 1×10⁻⁴ M and lower detection limits of 1.5×10⁻⁷ M.     

A Reliable Electrochemical Sensor Based on Functionalized Magnetite Nanoparticles for Over-the-counter Allergy Medication Abuse Sensing in Biological Fluids

Diphenhydramine (DIPH) has become one of the world‘s most widely abused over-the-counter medications. In addition to relieving allergy symptoms, it is also recognized for causing elevated energy and mild euphoric effects. The U.S. Food and Drug Administration (FDA) has recently warned about serious problems at high doses including heart problems, seizures, coma or even death among addicted teenagers. Herein, a simple, cost-effective, and reliable nanocomposite based electrochemical sensor was designed for DIPH quantification in biological fluids. Introducing the functionalized Fe₃O₄ nanoparticles (NPs) into the inner-filling solution and the PVC-based ion sensing membrane has been employed and compared to the classical potentiometric approach. The nanoparticles were incorporated to endorse in situ cooperative ion-pairing interaction between the ionophore and DIPH, and to improve the selectivity and detection limit (9.5×10⁻⁸ M). Nernstian potentiometric response was achieved for DIPH over the concentration range of 1.0×10⁻⁷ to 1.0×10⁻² M with a slope of 59.0±0.2 mV/decade. Inherent merits of the proposed sensor include fast response time (6 s), superior stability (60 days) with higher sensitivity and selectivity towards DIPH without interference from co-formulated drugs and several ions commonly found in biological matrices. The proposed sensor was successfully applied to the potentiometric determination of DIPH in different biological fluids (plasma and human milk) with an average recovery of 99.06±1.95 % and 100.34±1.92 %, respectively. As a consequence, the developed ISE might be the ideal choice for in-line DIPH measurements in plasma samples to identify overdose ingestion and its related symptoms, as well as for quality-control laboratories without prior treatments.     

聚1-氨基蒽醌在二次锂电池正极材料中的应用

采用化学方法合成聚1-氨基蒽醌并用于二次锂电池正极材料,通过红外光谱、扫描电镜、粒度测试、循环伏安以及充放电测试等方法对材料的官能团结构、微观形貌、颗粒大小以及电化学性能等进行了研究与分析.实验表明,与金属锂组成二次锂电池后,聚1-氨基蒽醌达到了218.3 mAh•g－1的首次放电容量,经过25次循环后仍可保持较高的充放电效率.由于材料具有较高的能量密度且不含对环境有污染的元素S,因此是二次锂电池非常有希望的正极材料.     

Halogen-Bonding Strapped Porphyrin BODIPY Rotaxanes for Dual Optical and Electrochemical Anion Sensing

Anion receptors employing two distinct sensory mechanisms are rare. Herein, we report the first examples of halogen-bonding porphyrin BODIPY [2]rotaxanes capable of both fluorescent and redox electrochemical sensing of anions. ¹H NMR, UV/visible and electrochemical studies revealed rotaxane axle triazole group coordination to the zinc(II) metalloporphyrin-containing macrocycle component, serves to preorganise the rotaxane binding cavity and dramatically enhances anion binding affinities. Mechanically bonded, integrated-axle BODIPY and macrocycle strapped metalloporphyrin motifs enable the anion recognition event to be sensed by the significant quenching of the BODIPY fluorophore and cathodic perturbations of the metalloporphyrin P/P^+. redox couple.     

Determination of Isotherm for Acetate and Formate Adsorption at Pt(111) Electrode by Fast Scan Voltammetry (cited: 3)

Fast scan voltammetry is an efficient tool to distinguish oxidative/reductive adsorp-tion/desorption from that for bulk reaction. In this work, we provide a methodology that the isotherm of oxidative/reductive adsorption desorption processes at electrode surface canbe obtained using just one solution with relatively low reactant concentration, by taking the advantage of varying the potential scan rate (relative of the diffusion rate) to tune the adsorption rate and proper mathematic treatment. The methodology is demonstrated bytaking acetate adsorption at Pt(111) in acidic solution as an example. The possibility for ex-tension of this method toward mechanistic studies of complicated electrocatalytic reactions is also given.     

A High Sensitive TNT Sensor Based on Electrochemically Reduced Graphene Oxide‐Poly(amidoamine) Modified Electrode

In this paper, the electrochemically reduced graphene oxide‐poly(amidoamine) hybrid (ErGO‐PAMAM) have been used for fabrication of TNT electrochemical sensor. The prepared modified electrode is characterized with X‐ray photoelectron spectroscopy (XPS), fourier transform infrared spectroscopy (FT‐IR), electrochemical impedance spectroscopy (EIS), energy‐dispersive X‐ray (EDX) spectroscopy, scanning electron microscopy (SEM) and atomic force microscope (AFM). Based on obtained results, it is can be seen that the ErGO‐PAMAM/GCE has high response to TNT than the other graphene based modified electrodes. The resulting electrochemical sensor exhibited good response to TNT with linear range from 0.05 to 1.2 ppm with a low detection limit of 0.0015 ppm.     

聚苯胺和聚吡咯膜电极对Fe（Ⅱ）和Sb（Ⅲ）电催化作用

Ｆｅ（Ⅱ）和Ｓｂ（Ⅲ）的氧化还原峰电流在聚苯胺（ＰＡｎ）和聚吡啶（ＰＰｙ）膜电极上比在铂丝电极上高出一倍至数倍。在膜电极上氧化峰电位与还原峰电位之差值（△Ｅｐ）也比在铂丝电极上显著减小．说明两种膜电极对Ｆｅ（Ⅱ）和Ｓｂ（Ⅲ）离子的电极反应有较好的电催化活性。在电位扫描速度较低时，两种离子在聚合物膜电极上的氧化和还原反应的催化活性相近。     

Electrochemical Sensor Based on Thioether Oligomer Poly(N‐vinylpyrrolidone)‐modified Gold Electrode for Bisphenol A Detection

Presently, bisphenol A (BPA) has been added to the list of substances of very high concern as endocrine disruptors. According to the literature, exposure to bisphenol A even at low doses may result in adverse health effects. In this study, electrochemical sensor of Bisphenol A based on thioether DDT‐Poly(N‐vinylpyrrolidone) oligomer has been developed. The thioether oligomer, which is capable of recognizing BPA, was prepared and used for gold electrode modification. The characterization of the modified gold electrode and the synthesized thioether oligomer were carried out by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), atomic force microscopy (AFM), Fourier‐transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance spectroscopy (¹H NMR) and Size exclusion chromatography (SEC). Obtained results indicate that the modified electrode shows good electrochemical activity, good sensitivity and reproducibility for BPA detection. It exhibited a good linear relationship ranging from 1 to 20 pg/mL, and the detection limit was found to be 1.9 pg/mL at S/N=3. Several interfering species such as hydroquinone, phenol and resorcinol were used and their behaviors on the modified gold electrode were investigated.