Surface Electrochemical Properties Research Articles

Internal Force Mechanism of Pisha Sandstone as a Soil Amendment to Improve Sandy Soil Structural Stability in Mu Us Sandy Land

Compounding Pisha sandstone (PSS) with sandy soil in Mu Us Sandy Land is a viable agronomical measure to effectively reduce soil erosion and improve soil quality due to the complementary characters and structures of the two materials. Aggregate stability is an important indicator to assess sandy soil erosion resistance and quality, which could be largely affected by soil surface electrochemical properties and particle interaction forces. However, the effect of the compound ratio and particle interaction forces on the aggregate stability of compound soils with Pisha sandstone and sandy soil is still unclear. Therefore, in this study, the electrochemical properties, particle interaction forces, and their effects on the aggregate stability of PSS and sandy soil at five volume ratios (0:1, 1:5, 1:2, 1:1, and 1:0) were determined to clarify the internal force mechanism of PSS to increase sandy soil structural stability in a 10-year field experiment. Experiments were measured by a combined method for the determination of surface properties and aggregate water stability. A ten-year field study revealed that the incorporation of Pisha sandstone significantly enhanced the soil organic carbon (SOC) and cation exchange capacity (CEC) (p < 0.05), while the CEC value notably increased from 4.68 to 13.76 cmol·kg−1 (p < 0.05). The soil surface potential (absolute value) and the electric field intensity gradually decreased with the increase in the Pisha sandstone content. For the compound soil particle interaction force, the addition of Pisha sandstone enhanced the van der Waals attraction force, reduced the net repulsive force between compound soil particles, and promoted the agglomeration of aeolian sandy soil. The overall trend of the aggregate breaking strength of compound soils under different addition ratios of PSS was 1:0 > 1:1 > 0:1 > 1:5 > 1:2. When the Pisha sandstone content in the compound soils was <50%, the aggregate stability was mainly influenced by compound soil particle interaction forces, and the interaction force increase was the key reason for the aggregate breakdown. When the Pisha sandstone content in the compound soils was ≥50%, the aggregate stability was affected by the combined effects of the compound soil particle composition and particle interaction forces. These results indicate that PSS addition ratios and particle interaction force are important factors affecting the structural stability of compound soils, in which the volume ratio of PSS to sandy soil of 1:2 is the appropriate ratio. Our study provides some theoretical references for further understanding of the compound soil structure improvement and sandy soil erosion control in Mu Us Sandy Land.

Tailoring electroless Ni-W-P polyalloy coatings: Unveiling the synergistic impact of cerium addition and annealing on surface functional properties

Electroless deposition of Ni-based coatings is a cost-effective solution to augment the surface mechanical and electrochemical properties of engineering components. This work explores the influence of addition of rare-earth element Ce on the characteristics of Ni-W-P coatings. The concentration of Ce salt in the deposition bath was varied in the range 0–14 mg/L, and the highest deposition rate was for the solution with 8 mg/L Ce. A homogeneous distribution of Ce over the coated surfaces was observed, and the share of Ce in the composition of the deposition varied monotonically with the Ce concentration in solution. Further, the coating surface compositions also depended on the Ce-content. Coating obtained using 8 mg/L Ce was found to have significantly improved scratch hardness (8.49 GPa), fracture toughness (7.05 MPa.m1/2), specific wear rate (3.1 × 10−6 mm3/N.m) and corrosion protection efficiency (94.16 %) as compared to the coating without Ce (3.87 GPa, 3.39 MPa.m1/2, 9.03 × 10−6 mm3/N.m, and 45.44 %, respectively). Interestingly, the ability of the coating to inhibit biofilm formation on the surface initially increased with increasing Ce content, but this effect also diminished above 8 mg/L Ce. Additionally, annealing the coatings caused further alterations in the microstructures, resulting in improvement in the microhardness, scratch, wear, and biocorrosion resistance, but at the cost of compromised corrosion resistance. Properties of such annealed coatings also depended on the annealing temperature. Therefore, this study indicates that a wide spectrum of combinations of surface physical, mechanical, and electrochemical properties can be achieved by controlling only two processing conditions, i.e., the Ce concentration, and the annealing temperature.

The influence of rolling on the corrosion and wear resistance of the MAO coating on ZM5 alloy

PurposeThe impact of rolling on the performance of micro arc oxidation (MAO) coatings on ZM5 alloy has been underreported. The purpose of this study is to explore the correlation between rolling and the failure mechanism of MAO coatings in greater depth.Design/methodology/approachThe influence of rolling on the corrosion and wear properties of MAO coating was investigated by phase structure, bond strength test (initial bond strength and wet adhesion), electrochemical impedance spectroscopy and wear test. The change of the surface electrochemical properties was studied by first principles analysis.FindingsThe results showed that the MAO coating on rolled alloy had better corrosion and wear resistance compared to cast alloy, although the structure and component content of two kinds of MAO coating are nearly identical. The difference in interface bonding between MAO coating and Mg substrate is the primary factor contributing to the disparity in performance between the two types of samples. Finally, the impact of the rolling process on MAO coating properties is explained through first-principle calculation.Originality/valueA comprehensive explanation of the impact of the rolling process on MAO coating properties will provide substantial support for enhancing the application of Mg alloy anticorrosion.Graphical abstract

Electropolishing of gold and gold alloys in HCl-glycerol-ethanol electrolytes

Electropolishing or electrochemical polishing (EP) is an ultrafinishing process that improves esthetic, technical and functional properties of metallic surfaces by reducing their roughness. This process is based on anodic dissolution of the workpiece through an oxidation reaction. For many years, cyanide-based electrolytes were used to electropolish precious metals like gold and its alloys. The need for safer working conditions encouraged the replacement of cyanide by other complexing agents, mainly thiourea. However, the latter is also harmful. Therefore, the aim of this work is to electropolish pure gold and 18k jewelry gold alloys (yellow, rose, red and gray) in a cyanide-free electrolyte, to evaluate the electrochemical behavior and the influence of different parameters. For this purpose, a previously reported solution based on hydrochloric acid and glycerol was used. In the first part of the study, the influence of chloride concentration on pure gold EP was determined by electrochemical techniques and surface properties analysis. The effects of adding ethanol to electrolyte composition and of variating rotation speed were also evaluated. The best results were obtained for a HCl 50% vol. - Glycerol 25 % vol. - Ethanol 25 % vol. electrolyte at a rotation speed of 1000 rpm. In the second part of the study, this solution was used to electropolish 18 K gold alloys. Silver-containing alloys were not uniformly polished due to the formation of an AgCl film on the surface that partially masks the substrates.

Selective concentration of iron, titanium, and zirconium substrate minerals within Gregory's diverticulum, an organ unique to derived sand dollars (Echinoidea: Scutelliformes).

Gregory's diverticulum, a digestive tract structure unique to a derived group of sand dollars (Echinoidea: Scutelliformes), is filled with sand grains obtained from the substrate the animals inhabit. The simple methods of shining a bright light through a specimen or testing response to a magnet can reveal the presence of a mineral-filled diverticulum. Heavy minerals with a specific gravity of >2.9 g/cm3 are selectively concentrated inside the organ, usually at concentrations one order of magnitude, or more, greater than found in the substrate. Analyses of diverticulum content for thirteen species from nine genera, using optical mineralogy, powder X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy, as well as micro-computed tomography shows the preference for selection of five major heavy minerals: magnetite (Fe3O4), hematite (Fe2O3), ilmenite (FeTiO3), rutile (TiO2), and zircon (ZrSiO4). Minor amounts of heavy or marginally heavy amphibole, pyroxene and garnet mineral grains may also be incorporated. In general, the animals exhibit a preference for mineral grains with a specific gravity of >4.0 g/cm3, although the choice is opportunistic and the actual mix of mineral species depends on the mineral composition of the substrate. The animals also select for grain size, with mineral grains generally in the range of 50 to 150 μm, and do not appear to alter this preference during ontogeny. A comparison of analytical methods demonstrates that X-ray attenuation measured using micro-computed tomography is a reliable non-destructive method for heavy mineral quantification when supported by associated analyses of mineral grains extracted destructively from specimens or from substrate collected together with the specimens. Commonalities in the electro-chemical surface properties of the ingested minerals suggest that such characteristics play an important role in the selection process.

Preparation and characterization of calcite/biochar composites fabricated by co-pyrolysis technique

In this study, calcite/biochar (CAL/BC) porous composites were synthesized via the co-pyrolysis of coconut shell (CS) and calcite (CAL) at temperatures ranging from 500°C, 600°C and 700°C. The surface morphology, chemical composition, and electrochemical properties of the CAL/BC composites were characterized using scanning electron microscopy (SEM), inductively coupled plasma mass spectrometry (ICP-MS), BET analysis, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and electrochemical workstation. The results revealed that CAL/BC composites produced at 700°C exhibited the highest adsorption capacity for Pb solution among all synthesized materials, with a maximum adsorption capacity of 79.8 mg/g. Furthermore, excellent regeneration properties were observed for all CAL/BC composites prepared at 500°C, 600°C, and 700°C, with a high removal rate of Pb maintained after four adsorption-desorption cycles. The CAL/BC composite synthesized at 700°C exhibited the lowest corrosion current density of 6.314×10−6A/cm2, indicating the most outstanding corrosion resistance among all three CAL/BC composites. Conversely, the highest corrosion current density of 8.871×10−5A/cm2 was observed in the CAL/BC composite prepared at 500°C, indicating the most inadequate corrosion resistance of this composite.

Rapid room-temperature synthesis of disposable Co nanoparticles modified 3D N-doped porous carbon electrode device for efficient electrochemical detection of veterinary drug and pesticide residue

In this work, Co-based metal-organic framework (ZIF-67) coupled polyimide (ZIF-67/PI) film was fastly and effectively transformed into flexible Co nanoparticles modified 3D N-doped porous carbon (Co@3D NPC) electrode device using simple laser ablation technique at room temperature. Compared with 3D NPC electrode device that derived from pure polyimide film, Co@3D NPC exhibited significantly enhanced electron transfer ability, physical adsorption ability and electrochemically active surface area. By adjusting the laser power and ZIF-67 concentration, the surface morphology and electrochemical property of the Co@3D NPC electrode devices can be easily controlled. Furthermore, the fabricated flexible Co@/3D NPC electrode device exhibited exceptional electrochemical activity for the sensitive detection of clozapine and albendazole, two kinds of common veterinary drug and pesticide. The detection sensitivity of Co@/3D NPC electrode device reached to 410.47 μA μM−1 cm−2 and 580.33 μA μM−1 cm−2, with detection limits as low as 2.8 nM and 2.5 nM for clozapine and albendazole, respectively. Besides, the Co@/3D NPC electrode device demonstrated excellent stability and accuracy. Given the advantages of laser ablation technology, including its low cost, scalability, and high stability, the reported Co@/3D NPC electrode device holds significant potential for practical applications in the field of electrochemical analysis.

Fabrication of a highly active β-PbO2-Co3O4 electrode for zinc electrowinning by pulse electrodeposition: Characterization and catalytic performance analysis

High oxygen evolution overpotential and low corrosion resistance are regarded as the main drawbacks of anode materials in zinc electrowinning. To improve the electrocatalytic activity of oxygen evolution reactions (OER) and reduce energy consumption in zinc electrowinning, a Co3O4 nanoparticle-modified PbO2 anode was prepared on a Ti substrate with Sn-SbOX as an interlayer through pulse electrodeposition. The surface morphology, phase composition, and electrochemical properties of the as-prepared anode were systematically investigated. The introduction of Co3O4 nanoparticles refined the crystal size of PbO2 and increased the surface roughness of the anode. Electrochemical tests suggested the excellent electrocatalytic activity of the Co3O4 nanoparticle-modified PbO2 anode. Density functional theory (DFT) calculations revealed that Co3O4 nanoparticles reduced the OER free energy (1.58 eV) and that pulse electrodeposition reduced the PbO2 crystal size and increased the active surface area of the anode. In the simulated zinc electrowinning test, an improved current efficiency (90.6 %) was achieved, and the low energy consumption (2,508.29 kW·h) for zinc production per ton was significantly reduced as compared with that for the conventional Pb-0.75 %Ag anode. The lifetime of the modified electrode is increased by approximately 36.8 %. This provides a reference for the design and development of anode materials with high oxygen evolution activity and strong corrosion resistance in zinc electrowinning systems.

In situ synergistic reduced graphene oxide-boron carbon nitride nanosheet heterostructures for high-performance fabric-based supercapacitors.

We develop a new type of heterostructure nanocomposite made of reduced graphene oxide-boron carbon nitride nanosheets (rGO-BCN) by B-C covalent bonds. The rGO-BCN nanocomposite delivers a large specific surface and excellent electrochemical properties, and is then constructed into flexible fabric-based high-performance supercapacitor electrodes based on the microfluidic electrospinning technology.

Influence of Precursor Type on Activated Carbon Prepared by Phosphoric Acid-Chemical Activation for Supercapacitor Applications

Phosphoric acid can be used to activate different precursors and produce activated carbon (AC), a porous material with high adsorption capacity and surface area. This research shows how AC is made using different locally available precursors, namely amla seeds and harro seeds. We compare how the carbonization temperature and the precursor type affect the surface area, pore structure, and electrochemical properties of the AC. We use different methods to analyze the AC samples, such as scanning electron microscopy, surface area, methylene blue number, iodine number, and cyclic voltammetry. We show that the best conditions for making AC depend on the type of precursor and the activation temperature.

Influence of Galvanic Interaction between the Iron Grinding Medium and Chalcopyrite on Collectorless Flotation Behavior of Chalcopyrite: Experimental and Density Functional Theory Study.

The eco-friendly flotation process for chalcopyrite is economically significant and promotes sustainable development in mining. Collectorless flotation is a green and clean method for chalcopyrite utilization, but galvanic interactions during the grinding process can affect the surface structure, chemical composition, and electrochemical properties, impacting collectorless flotation recovery. This article uses a self-made device and flotation experiments to study galvanic interactions and their effects on surface oxidation and collectorless flotation behavior under different grinding conditions (including mineral particle size, slurry water content, pressure, and galvanic interaction time). The impact of galvanic interaction on the surface chemical composition and electrochemical properties of chalcopyrite is studied using high-performance liquid chromatography (HPLC), X-ray photoelectron spectroscopy (XPS), and electrochemical tests. Additionally, the effect of the galvanic interaction on the surface structure is analyzed with density functional theory. XPS and HPLC results show that iron grinding media contact with chalcopyrite, reducing elemental sulfur content of the chalcopyrite surface, improving hydrophilicity, and decreasing chalcopyrite collectorless flotation recovery. Grinding conditions, such as mineral particle size, slurry water content, and galvanic interaction time, significantly impact collectorless flotation and can be regulated to optimize results.

Study on the passivation effect and corrosion mechanism of an environmentally protective insulating coating on non-oriented electrical steel

In this study, we successfully developed three insulating coatings for non-oriented electrical steel. These coatings were composed of phosphate film-forming agents, passivating agents (vanadate, cerium nitrate, and zirconate), and polyurethane dispersants. The surface morphology, composition, electrochemical properties, and corrosion resistance of the three coatings were characterized using scanning electron microscopy (SEM), field-emission electron probe microanalyzer (EPMA), confocal Raman microscopy (CRM), scanning vibration electrode technology (SVET), electrochemical testing, and neutral salt spray experiments. The passivating agent substantially enhanced the compactness of the coating by forming a composite film with the phosphate film-forming agent, which prevented direct contact between the matrix and the corrosive medium and significantly improved the corrosion resistance of the coating. The zirconate passivator significantly increased the compactness of the coating, forming a composite film composed of continuous three-dimensional metals or metalloid oxides on the matrix surface, thereby providing a good shielding effect for the substrate. The incorporation of polyurethane increased fluidity and formed a cross-liked network structure with the composite coatings, enhancing corrosion resistance. The overall properties of the coating that had a zirconate passivator (TZB) demonstrated the best performance among the three systems, surpassing industrial standards, and fulfilling the application requirements for non-oriented electrical steel.

Electrochemical Scanning Probe Microscopy Evaluation of Li-Ion Battery Cathode Degradation through in Situ Oxygen Evolution Measurement and Interfacial Property Characterization

Degradation processes involving oxygen evolution significantly limit the performance, reversibility, and capacity of high energy density Li-ion battery (LiB) cathodes. In addition, oxygen evolution processes create hazardous conditions for LiB operation. Despite the importance of these processes, characterization of evolved O2 with sufficient spatial and temporal versatility is hampered by the complex setups required to perform electrochemical mass spectrometry, the gold standard for evaluating this process. Recently, we introduced a scanning electrochemical microscopy (SECM) approach that enables in-situ, real-time (i.e., few ms temporal resolution), chemically selective detection of O2.[1] Measurements were accomplished by positioning an SECM probe (i.e., an Au ultramicroelectrode) near operating cathode surfaces for detecting O2 via the oxygen reduction reaction (ORR). The superior signal-to-noise of this method enabled the observation of two peaks corresponding to a steady-state evolution at high voltage and a transient O2 evolution at low voltage on materials such as lithium cobalt oxide (LCO) and NMC electrodes.Here, we expand the capabilities of our technique by incorporating correlated measurements aimed at understanding how oxygen evolution profiles are related to surface electrochemical and mechanical properties. Specifically, we will focus on the use of feedback-mode SECM and the use of reactive mediators to evaluate the changes in the rates of electron transfer measured on materials undergoing O2 and after structural degradation. Furthermore, the use of electrochemical AFM allows us to measure the mechanical properties of these interfaces, in an attempt to tie the structural changes and the evolution of oxidizing species with the formation of cathode-electrolyte interfaces. Altogether, these multimodal SECM and AFM methods elucidate the manifold chemical, structural, and performance changes underpinning LiB cathode operation.[1] Mishra, A.; Sarbapalli, D.; Hossain, M.S.; Gossage, Z.T.; Li, Z.; Urban, A.; Rodríguez-López, J. Highly Sensitive Detection and Mapping of Incipient and Steady-State Oxygen Evolution from Operating Li-Ion Battery Cathodes via Scanning Electrochemical Microscopy. J. Electrochem. Soc., 2022, 169, 086501. Figure 1

Elevating superpacitor performance: Enhancing electrochemical efficiency with transition metal-doped polyaniline electrode

Polyaniline (PANI) stands out as a highly favored electrically conductive polymer, extensively investigated for its potential as an electrode material in the advancement of energy storage systems. Nevertheless, the practical utilization of PANI is hindered by its inadequate stability, posing limitations on its wider application. To address this issue, doping with carbon and carbon-based materials or transition metals is frequently employed. In this study, transition metals Ag+ and Fe3+ were doped into the of polyaniline PANI structure to enhance its surface area, conductivity, and electrochemical properties. The doping of Ag+ and Fe3+ into the PANI structure resulted in a significant increase of up to three times in the surface area and conductivity of PANI. Electro-Paramagnetic Resonance (EPR) spectra analysis showed a substantial change in the intensity value with Ag+ doping, while no significant alteration was observed in the g-factor values. Electrochemical analyses demonstrated that both Ag+ and Fe3+ doping improved the specific capacitance, energy density, and power density of PANI in both symmetric and asymmetric designs. Furthermore, the utilization of electron paramagnetic resonance (EPR) spectroscopy complemented the comprehensive electrochemical analysis by offering valuable insights into the defect structures present in the electrode materials.

Study the effect of rGO on the porous binary Zn0.25Cu0.75S nanocomposite deposited on Ni-foam electrode for high performance energy storage devices

Supercapattery is the combination of battery and supercapacitor, which has the benefits of both devices like high power density, cycle stability, and greater energy density. Using a simple hydrothermal method, we synthesized zinc sulfide (ZnS), copper sulfide (CuS), and zinc copper sulfide (ZnCuS). The Zn0.25Cu0.75S@rGO nanocomposite electrode exhibited excellent electrochemical results, functioning at 1.4 A/g in a three-electrode assembly with an extraordinary specific capacitance of 2935 F/g. Brunauer-Emmett-Teller (BET) measurements and electrochemical impedance spectroscopy (EIS) studies show the improvement in surface area and electrochemical properties of the material. The hybrid device (Zn0.25Cu0.75S@rGO//AC) showed an extraordinary specific capacity of 150 C/g at 1.2 A/g with Pb of 2800 W/kg and Ed of 36.6 Wh/Kg. The supercapattery device exhibited an outstanding cyclic stability of 91 %. Our findings show that Zn0.25Cu0.75S@rGO is more suitable for storage devices as an electrode material.

Assessment of oxygenated polycyclic aromatic hydrocarbon cytotoxicity using TiO2-MXene/MWCNTs/PDA/GCE electrochemical sensor

Oxygenated polycyclic aromatic hydrocarbons (OPAHs) present in the environment can enter the skin through direct contact and long-term exposure can increase the risk of skin inflammation, allergic reactions and skin cancer. In this study, a titanium dioxide-two-dimensional transition metal carbide/multi-walled carbon nanotubes/polydopamine/glassy carbon electrode (TiO2-MXene/MWCNTs/PDA/GCE) electrochemical biosensor was prepared to evaluate the cytotoxicity of OPAHs based on the changes in the content of xanthine/guanine (X/G) during cellular metabolism. The TiO2-MXene/MWCNTs/PDA/GCE exhibited excellent electrocatalytic activity and sensitivity. The surface morphology, structure and electrochemical properties of TiO2-MXene/MWCNTs/PDA composite material were characterized using scanning electron microscopy, X-ray diffraction and cyclic voltammetry. Human skin fibroblast cells (HFF-1) were used as model cells, and the cell viability was evaluated based on the electrochemical signal changes of X/G. When exposed to OPAHs for 30 h, the half-maximal inhibitory concentrations (IC50) of 1,4-benzoquinone (1,4-BQ), 1,2-naphthoquinone (1,2-NQ), and 9,10-phenanthrenequinone (9,10-PQ) on HFF-1 cells were 291.88, 67.72, and 4.44 µmol·L−1, respectively, which were lower than the IC50 values of 1075.51, 113.96, and 9.63 µmol·L−1 obtained using the traditional MTT assay, indicating higher sensitivity of the sensor. This study achieved sensitive detection of purines in HFF-1 cells, providing a technical method for evaluating the cytotoxicity of persistent organic pollutants OPAHs in the environment.

Degradation of trichloroethylene by biochar supported nano zero-valent iron (BC-nZVI): The role of specific surface area and electrochemical properties

Direct electron transfer and the involvement of atomic hydrogen (H⁎) are considered the main mechanisms for reductive dechlorination promoted by nano zero-valent iron (nZVI) supported on highly conductive carbon. It is still unclear how precisely H⁎, the specific surface area, and the electrochemical characteristics contribute to biochar supported nano zero-valent iron (BC-nZVI) activity in chlorinated hydrocarbon contaminant removal. In this study, a range of BC-nZVIs were prepared by a liquid-phase reduction process, and the contributions of specific surface area and electrochemical performance to H⁎ generation and electron transfer have been assessed. The mechanism of trichloroethylene (TCE) dechlorination by BC-nZVIs has been evaluated in terms of removal efficiency and the ultimate degradation products. The results have demonstrated that BC-nZVIs exhibit a higher specific surface area and TCE degradation efficiency compared with the bare nZVI. Ethane, ethylene, and acetylene were the principal TCE degradation products. The elimination of TCE was not significantly affected by differences in BC-nZVI specific surface area, but electron transfer and sustained generation of H⁎ were dependent on the catalyst electrochemical characteristics. The electrochemical properties of biochar serve to lower the corrosion potential of nZVI, improving electronic transfer capability and reactivity and promoting direct electron transfer for the degradation of TCE. In addition, the enhanced electrochemical properties also facilitate the reaction of nZVI with water and can promote the sustained generation of H⁎. Generation of H⁎ played a key role in reductive dechlorination over BC-nZVIs, which was related to the properties of the biochar support. This study focuses on the role of H⁎ and electrochemical performance in TCE reductive dechlorination, and provides a theoretical foundation and experimental support for the practical application of BC-nZVIs.

Modification of a hollow fiber membrane with silver/multiwall carbon nanotube/polyaniline nanocomposite as a highly sensitive sensor for voltammetric measurement of antioxidant drug dipyridamole

In this study, a hollow fiber membrane (HFM was subjected to modification with a nanocomposite of silver/multi-walled carbon nanotube/polyaniline (AgNP/MWCNT/PANI). The sensor was utilized as a tool for voltammetric determination of the antioxidant drug Dipyridamole (DIP) in aqueous solution. The surface morphology and electrochemical properties of the proposed electrode were assessed through the use of Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX), and electrochemical impedance spectroscopy (EIS). The electrochemical performance of the electrode was analyzed using differential pulse voltammetry (DPV) and cyclic voltammetry (CV) techniques. All parameters that could potentially impact the application of the new electrode were thoroughly investigated. A linear correlation between oxidation current and DIP concentration was established within the range of 0.01–50.0 μM (R2 = 0.99), with a detection limit of 1.0 × 10−3 μM. The new electrode was successfully employed for the determination of DIP in real samples, including pharmaceutical formulations and biological samples.

A review of glycosaminoglycan-modified electrically conductive polymers for biomedical applications.

The application areas of electrically conductive polymers have been steadily growing since their discovery in the late 1970s. Recently, electrically conductive polymers have found their way into biomedicine, allowing the realization of many relevant applications ranging from bioelectronics to scaffolds for tissue engineering. Extracellular matrix components, such as glycosaminoglycans, build an important class of biomaterials that are heavily researched for biomedical applications due to their favorable properties. Due to their highly anionic character and the presence of sulfate groups in glycosaminoglycans, these biomolecules can be employed to functionalize conductive polymers, which enables the tailorability and improvement of cell-material interactions of conductive polymers. This review paper gives an overview of recent research on glycosaminoglycan-modified conductive polymers intended for biomedical applications and discusses the effect of different biological dopants on material characteristics, such as surface roughness, stiffness, and electrochemical properties. Moreover, the key findings of the biological characterization in vitro and in vivo are summarized, and remaining challenges in the field, particularly related to the modification of electrically conductive polymers with glycosaminoglycans to achieve improved functional and biological outcomes, are discussed. STATEMENT OF SIGNIFICANCE: The development of functional biomaterials based on electrically conductive polymers (CPs) for various biomedical applications, such as neural regeneration, drug delivery, or bioelectronics, has been increasingly investigated over the last decades. Recent literature has shown that changes in the synthesis procedure or the chosen dopant could adjust the resulting material characteristics. Hence, an interesting approach lies in using natural biomolecules as dopants for CPs to tailor the biological outcome. This review comprehensively summarizes the state of the art in the field of glycosaminoglycan-modified electrically conductive polymers for the first time, particularly highlighting the effect of the chosen dopant on material characteristics, such as surface morphology or stiffness, electrochemical properties, and consequently, cell-material interactions.

A nanoporous screen-printed carbon sensor for environmental and clinical monitoring of the antibiotic ciprofloxacin

A very sensitive, fast and simple electrochemical procedure using a nanoporous screen-printed carbon electrode (NPSPCE) was developed for the determination of the fluoroquinolone antibiotic ciprofloxacin (CFX). Changes in the surface morphology and electrochemical properties of the SPCE before and after pre-anodization were examined using scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). CV studies also demonstrated unequivocally adsorption controlled and irreversible oxidation of CFX. Using optimized conditions, the developed procedure is characterized by excellent selectivity and high sensitivity, allowing to achieve a very low limit detection (6.3 × 10−11 mol/L). The measurements taken allow us to consider the NPSPCE as a very effective tool for direct determination of CFX in samples with a complex matrix such as sewage and body fluids. The developed environment friendly sensor and procedure meet the requirements of green chemistry (reduction of toxic chemicals/reagents, and generation of minimal waste).