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The application of biomass‐based carbon materials in electrochemical sensing was limited due to their few active sites. So N and P double doped biomass pyrolytic carbon materials were designed in this paper. These gained materials were characterized by a series of characterization test techniques, and used as electrode modification to construct electrochemical sensors to detect baicalein (BA) and luteolin (LU). Under the best test condition, the minimum detectability of BA and LU was (7.8±0.25)×10−9 mol/L and (7.6±0.24)×10−9 mol/L (S/N=3), respectively. And the sensor performed well in the Shuanghuanglian oral liquid and the healthy human urine samples. [ABSTRACT FROM AUTHOR]

Chirality exists everywhere in nature, so chiral recognition is also an extremely important field. This paper explores the recognition of amino acid configuration by an electrochemical chiral sensing platform constructed with carbon nanomaterials (carbon quantum dots (CQDs) as the substrate material) combined with chiral selectors (chitosan (CS)). CQDs/CS, which is bonded by intermolecular force, and CQDs‐CS, which is formed by covalent grafting through amidation, are selected as electrochemical chiral recognition materials, and a series of characterization methods are carried out to indicate the successful preparation of the materials, and then attached to the glass carbon electrode (GCE), forming a chiral sensing platform for amino acid enantiomers. The differential voltammetry (DPV) method was used to convert the chemical signal into electrical signal. The results showed that compared with CQDs/CS, CQDs‐CS had better enantiomer resolution to tryptophan (Trp), and the peak current ratio (IL/ID) was 2.28. [ABSTRACT FROM AUTHOR]

In this paper, ultrathin graphene (GN) nanosheets were uniformly decorated with nickel (Ni) nanoparticles, as confirmed by scanning electron microscopy and transmission electron microscopy. This GNNi hybrid exhibited excellent accumulation and catalytic capacity for the simultaneous detection of sunset yellow and tartrazine, two colorants commonly found mixed in foodstuffs. The electrochemical reaction mechanism of sunset yellow and tartrazine were studied in detail on the GNNi nanocomposite modified glassy carbon electrode. In square wave voltammetry measurements, the oxidation peak potentials of sunset yellow and tartrazine were separated by about 250 mV. This novel proposed voltammetric method has good selectivity which was successfully applied for the simultaneous determination of sunset yellow and tartrazine in some food sample extracts. [ABSTRACT FROM AUTHOR]

This paper describes a highly sensitive and label-free electrochemical immunosensor for the detection of 1-pyrenebutyric acid (PBA) which is based on a graphene (GS), chitosan (CS), and ionic liquid (IL) composite modified glassy carbon electrode (GS-CS-IL/GCE). The modification process was monitored by transmission electron microscopy (TEM) and cyclic voltammetry (CV). Due to the synergistic effects of GS, CS, and IL, the biosensor exhibits excellent selectivity to PBA. The current response of the proposed immunosensor decreases linearly at two concentration ranges from 0.01 to 5 and from 5 to 150 ng mL−1 with a detection limit of 0.01 ng mL−1. [ABSTRACT FROM AUTHOR]

This work demonstrates that quadruple‐disk electrodes with an innovative design, iridium‐platinum, platinum‐glassy carbon, and iridium‐glassy carbon can effectively function as a single sensor and act as a voltammetric electronic tongue in food profiling. The key strategy used was a novel technique called double‐sampled differential square‐wave voltammetry (DSSWV), which increased the resolution and enabled extraction of the full, hidden information available in the measuring signals. Four clustering validity indices, namely the Calinski – Harabasz index, Davies – Bouldin index, Silhouette index and gap statistics were employed to select the optimal sensor and methodology for interpreting the current samples. The best expected results were obtained using an iridium‐platinum electrode combined with overall cathodic potential modulation using the DSSWV technique. Principal component analysis and polar dendrogram confirmed the correct clustering of different isotonic beverages. However, it was also demonstrated that in some variants of measurement and signal interpretation, it was not possible to group the samples appropriately. [ABSTRACT FROM AUTHOR]

Hybrid magnetite/carbon quantum dots (MagNP/C-dots) were prepared and their characterization performed by high resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Because of their suitable magnetization and electrochemical properties, they were used as versatile electrode modifiers after magnetically confining onto screen printed carbon electrodes (SPE), with the aid of a miniature external magnet. The reported strategy introduces a convenient procedure for assembling modified electrodes, since the nanoparticles can be easily released by removing the magnet. The non-enzymatic magnetic biosensor showed excellent performance in the determination of NADH at the concentration range 2×10−7 to 5×10−6 mol L−1, exhibiting a sensitivity of 0.15 μmol L−1 and detection limit of 20 nmol L−1. The MagNP/C-dots/SPE sensor was also successfully applied for the determination of NADH in serum samples. The interference of typical biological molecules has also been investigated. [ABSTRACT FROM AUTHOR]

A novel, facile fabrication, based on electrochemically reduced graphene oxide (ErGO), grafted with Pt nanoparticles and Nafion hybrid nano-composite (ErGO-Pt/Nafion) on the surface of edge plane pyrolytic graphite (EPPG) has been reported. The fabricated sensor has been used for the sensitive and selective determination of efavirenz (EFZ), a well-known drug for HIV infections. The ErGO-Pt/Nafion film was characterized by Field Emission Scanning Electron Microscopy (FE-SEM), Energy-dispersive X-ray spectrometry (EDS) and Electrochemical Impedance Spectroscopy (EIS). The experimental results reveal that the modified sensor displays an excellent electrocatalytic activity towards the oxidation of EFZ and exhibits a large linear dynamic relationship in the range of 0.05 μM to 150 μM, with a detection limit of 1.8 nM. Practical utility of the developed sensor has been demonstrated by determining the EFZ in biological fluids and pharmaceutical samples and a low detection limit with high sensitivity observed makes it valuable for the clinical diagnosis. [ABSTRACT FROM AUTHOR]

L‐methionine (L−Me) deficiency in human body leads to several complications. In the present work, graphitic carbon nitride nanosheets (GCN−S) modified glassy carbon electrode (GC/GCN−S) was developed as a cost effective electrochemical sensor for L−Me. The oxidation of L−Me at bare GC electrode shows an ill‐defined peak and it was unstable whereas a well‐defined stable oxidation peak was obtained at GC/GCN−S electrode. While increasing L−Me concentration from 100 nM to 0.2 mM, the amperometric current increases linearly with R2=0.9901 and LOD was found to be 0.32 nM (S/N=3). Finally, GC/GCN−S electrode was used to determine L−Me in blood serum samples. [ABSTRACT FROM AUTHOR]

Electrochemically reduced glassy carbon (r-GC) showed a superior electrochemical sensing performance, compared to oxidized GC (ox-GC) and untreated GC for the oxidation of 4DNA bases and neurotransmitters (epinephrine, norepinephrine and serotonin). r-GC exhibited not only the largest current intensities of all redox biomolecules, but also displayed an excellent selectivity in detecting coexisting redox biomolecules. The enhanced performance of r-GC was attributed to the improved surface cleanliness of electrode and its catalytic surface functional groups. The results presented herein imply that simple electrochemical treatments are aviable method to produce sensitive and selective electrodes for label-free biosensing. [ABSTRACT FROM AUTHOR]

Suppressing the shuttling of dissolved lithium polysulfides (LiPSs) is an indispensable strategy to extend the cycling life of lithium‐sulfur (Li−S) batteries. One strategy is absorbing the LiPSs by modifying separator of Li−S batteries. Herein, we show a novel nitrogen‐doped graphitized carbon (NGC) derived from coconut shell, which was annealed by flash Joule heating at ultrahigh temperature within seconds. The NGC was coated on the polypropylene (PP) separator to prepare the modified PP separator, which enabled the Li−S batteries to work stably at 1 C with a low fading rate of 0.09 % from 788 mAh g−1. Microscopy analysis and Raman spectrum reveal that the high‐graphitization carbon with heavily nitrogen‐doping strengthens the adsorption of LiPSs in the charge/discharge process. [ABSTRACT FROM AUTHOR]

This work describes the development of a novel electrochemical sensor based on electrodeposition of copper oxide nanoparticles onto carbon nanoparticle (CNP) film modified electrode for the analysis of the anti-HIV drug, nevirapine (NEV). The electrochemical experiments were performed using linear sweep and cyclic voltammetry. Atomic force microscopy was applied for surface characterization of the deposited modifier film (CuO-CNP) on glassy carbon electrode (GCE). No oxidation peak was observed for NEV on the bare GCE, but both CNP-GCE and CuO-CNP-GCE showed a distinctive anodic response towards NEV with considerable enhancement (276-fold and 350-fold, respectively) compared to CuO-GCE. The mechanism of the electrocatalytic process on the modified electrode surface was investigated by cyclic and linear sweep voltammetry at various potential sweep rates and pHs of the buffer solutions. The modified electrode exhibited linear dynamic range in three concentration intervals (0.1-0.8, 1-10 and 10-100 µM) with a detection limit of 66 nM. The stability, reproducibility, and repetitive usability exhibited by the proposed modified electrode are good enough to make it a suitable sensor for the determination of NEV in real samples with complex matrices such as human blood serum. [ABSTRACT FROM AUTHOR]

Numerous carbon nanomaterials have been developed, such as graphene, carbon nanotubes, titanium carbide MXenes, fullerenes, carbon nanofibers, carbon-based quantum dots, boron doped diamond nanofilm, carbon black, single-walled carbon nanohorns, carbon nitride nanosheet, I N i -doped carbon, porous carbon nanomaterials, nanocarbon films with a high sp SP 3 sp content fabricated by unbalanced magnetron sputtering and carbon nanomaterial composites. Thanks to their extraordinary properties, carbon nanomaterials are involved in cutting-edge topics of various research fields. [Extracted from the article]

A novel sensor based on carbon black-gold nanoparticle nanocomposite modified screen-printed electrode (CB-AuNPs/SPE) for the detection of As(III) has been developed. The sensor was prepared modifying the SPE with CB and AuNPs by a drop casting automatable deposition. The As(III) was detected by CB-AuNPs/SPE using anodic stripping voltammetry, with a high sensitivity (673±6 µA µM−1 cm−2) and reaching a LOD of 0.4 ppb. Finally, CB-AuNPs/SPE has been applied to As(III) trace analysis in drinking water, obtaining satisfactory recovery values (99±9 %). [ABSTRACT FROM AUTHOR]

Rh17S15-Rh catalysts supported on acid-treated carbon black were prepared from RhCl3 by a facile method using sulfur source ((NH4)2S2O3) and reducing agent (NaBH4), followed by an additional thermal treatment at 650 °C in argon. The prepared catalyst comprised an Rh17S15 single crystalline phase and a zero-valent metal (Rh) phase supported on a conductive carbon. By XRD characterization, the constituent ratio of Rh17S15 to Rh in the electrocatalysts, ranging from 51-95 %, varied with the increase of amount of (NH4)2S2O3 or NaBH4. Morphologies of the resulting catalysts were characterized by transmission electron microscopy (TEM) technique. Most of particles were found to have a distribution of agglomerates ranging in size from 10 to 50 nm. In studying the effect of the constituent phases of chalcogenide electrocatalysts on oxygen reduction reaction activity, it is paramount to understand and optimize the structure sensitivity of the reaction, which will aid in determining the optimal ratio of Rh17S15 to Rh of the electrocatalyst. Activity and stability of the prepared catalysts were addressed using a series of cyclic voltammetry (CV) experiments in 1 M HCl electrolyte, in which the electrocatalyst of 95 % of Rh17S15 was found to be the most stable. The rotating disk electrode (RDE) experiment indicated the sulfide catalyst with 82 % of Rh17S15 showed the better performance for the ORR, which was discussed based on the compromise between the stability for the constituent phase of Rh17S15 in 1 M HCl and enhanced activity found for Rh phase. [ABSTRACT FROM AUTHOR]

Transition metal sulfides have emerged as promising materials in supercapacitor. In this work, we firstly developed an interface-induced superassembly approach to fabricate NiSx and CoSx nanoparticles, which based on ordered mesoporous carbon-graphene aerogel composites for supercapacitor electrodes. The obtained multi-component superassembled nanoparticles-carbon matrix composites have controllable 3D porous structure of multi-stage composite. The two-dimensional graphene interlaced to form a 3D framework with large sponge-like pores, and then the graphene surface was loaded with mesoporous carbon with mesoporous pore size and vertical orientation. The composites display high specific capacitance of 958.1 Fg-1 at 0.1 Ag-1. The capacitance retains about 97.3% after 3000 charging-discharging cycles at 2 Ag-1. These results indicate that the obtained OMC-GA-Ni3S2/Co4S3 is a promising material for electrochemical capacitors, which providing new technical methods and ideas for the research of new energy and analytical sensor materials in the fields of energy storage, photocatalysis, point-of-care testing devices and other fields. [ABSTRACT FROM AUTHOR]

The voltammetric behaviour of the macrolide based antibiotic: Erythromycin (ERT), Clarithromycin (CLA) and Azithromycin (AZT) was presented in this work. Carbon electrodes and platinum (Pt) electrode were applied as working electrodes. Cyclic voltamograms of each molecule in each electrode were recorded and similar electrochemical behaviour of macrolides was observed for all carbon based electrodes, which gave more defined current intensity peaks than platinum. Other organic compounds were tested trying to clarify electro‐active groups of macrolides. Experiments on mechanism of electrochemical reaction were performed, and studies on the influence of pH on peak current and peak potential were also carried out. [ABSTRACT FROM AUTHOR]

Lotus stem, Carbonization, Hydroquinone, Catechol, Nitrite, Simultaneous determination Keywords: Lotus stem; Carbonization; Hydroquinone; Catechol; Nitrite; Simultaneous determination EN Lotus stem Carbonization Hydroquinone Catechol Nitrite Simultaneous determination 1 1 1 04/12/21 20210401 NES 210401 The cover image is based on the Full Paper I Electrochemical Sensing Platform Based on Lotus Stem-derived Porous Carbon for the Simultaneous Determination of Hydroquinone, Catechol and Nitrite i by Zhenyong Lu et al., DOI: 10.1002/elan.202060478. Cover Feature: Electrochemical Sensing Platform Based on Lotus Stem-derived Porous Carbon for the Simultaneous Determination of Hydroquinone, Catechol and Nitrite (Electroanalysis 4/2021). [Extracted from the article]

A low cost synthesis of catalyst free carbon nano‐onions (CNOs) and nitrogen post doped CNOs (N−CNOs) using grapeseed oil is reported. Successful incorporation of nitrogen atoms into the lattice of CNOs was confirmed by XPS, resulting in 1.7 % nitrogen content. BET and Raman analysis showed an increase in the specific surface area and the ID/IG ratio of carbon, respectively after N incorporation. The specific capacitance of the CNOs increased upon nitrogen doping and as a result, N−CNOs exhibited superior electrochemical performance compared to pristine CNOs. Our results demonstrate that N−CNOs are a promising electrode material for energy storage in supercapacitors. [ABSTRACT FROM AUTHOR]

Detection of organophosphate pesticides is indispensable to improve the quality of the water and therefore required by the European Union law. Here, we propose a novel architecture of a pesticide biosensor where the enzyme and the electrode are placed into neighboring zones in the stripe form. This separation permits to use the optimal conditions for their immobilization resulting in undisrupted mechanical stability of the biosensor. The enzyme, acetylcholinesterase, generates thiocholine which is further oxidized at the carbon nanoparticles film electrode, exhibiting high electrocatalytic activity. The whole device was tested as a biosensor for malaoxon employing a wild or recombinant acetylcholinesterase. The latter allowed for incubation time decrease down to 10 minutes and lowered the detection limit to 0.25 nM. Moreover, the encapsulated enzyme activity was visualised by a scanning electrochemical microscopy. [ABSTRACT FROM AUTHOR]

Abstract: A novel approach to high loaded Pt core/carbon shell catalyst synthesis from a Pt‐aniline complex was reported. The Pt‐aniline complex was successfully synthesized by irradiating an ultrasound to the hexachloro platinic acid and aniline monomer mixture. The highly viscous nature of aniline leads to reproducible hexagonal plate like Pt‐aniline complex crystals. The chemical composition of the Pt‐aniline complex was identified as [PtCl2(C6H5NH2)2] with the help of NMR, XPS, HR ESI‐MS, and TGA analyses. Furthermore, the Pt‐aniline hexagonal plates were sintered at various temperatures like 400 °C, 500 °C, and 700 °C for an hour. This formed the highly dispersed carbon covered Pt nano particles with loading of 80.1 wt %, 81.3 wt %, and 83.4 wt % for HP‐4, HP‐5, and HP‐7, respectively. After supporting it on Vulcan XC‐72, Pt core/carbon shell pyrolyzed at a low temperature showed excellent performance in methanol oxidation reaction. In addition, Pt core/carbon shell prepared at a high temperature revealed excellent tolerance to methanol. [ABSTRACT FROM AUTHOR]

Solid like carbon paste electrodes (SCPEs) are built using different carbon materials namely carbon black N110, N220, N375, N772 and acetylene black. The electrochemical behavior of these electrodes and the influence of carbon black/paraffin ratio were studied and the results were discussed and compared to other electrodes prepared with graphite, mesoporous carbon and nanopowder carbon. Cyclic voltammetry, amperometry and electrochemical impedance spectroscopy were employed for their electrochemical and analytical characterizations. Amperometric measurements using N110, N220, N375 SCPEs with solid paraffin, showed a linear response of benzoquinone concentration with a detection limit of 75, 32 and 171 nM respectively. [ABSTRACT FROM AUTHOR]

A simple study using a fixed amount of mesoporous carbon (MSU-F-C) was performed for the comparison of pyranose oxidase (POx) and glucose oxidase (GOx) in their electrochemical performance under biosensor and biofuel cell operating modes. Even though the ratio of POx to GOx in the glucose oxidation activity per unit weight of MSU-F-C was 0.35, the ratios of POx to GOx in sensitivity and power density were reversed to be 6.2 and 1.4, respectively. POx with broad substrate specificity and an option of large scale production using recombinant E. coli has a great potential for various electrochemical applications, including biofuel cells. [ABSTRACT FROM AUTHOR]

Conventional (CPE) and miniaturized (m-CPE) carbon paste electrodes consisting of a carbon paste filled capillary were used for differential pulse voltammetric determination of chlortoluron in samples of river water and soil, in the latter case after the extraction by methanol. Britton-Robinson buffer pH 3 with low content of methanol was found to be optimal for the determination. The achieved determination limits were 2.8 µmol L−1 and 0.34 µmol L−1 in river water, and 3.1 and 4.3 µg g−1 in soil, using CPE and m-CPE, respectively. [ABSTRACT FROM AUTHOR]

In this work a partially reduced graphene oxide (p-RGO) modified carbon ionic liquid electrode (CILE) was prepared as the platform to fabricate an electrochemical DNA sensor, which was used for the sensitive detection of target ssDNA sequence related to transgenic soybean A2704-12 sequence. The CILE was fabricated by using 1-butylpyridinium hexafluorophosphate as the binder and then p-RGO was deposited on the surface of CILE by controlling the electroreduction conditions. NH2 modified ssDNA probe sequences were immobilized on the electrode surface via covalent bonds between the unreduced oxygen groups on the p-RGO surface and the amine group at the 5′-end of ssDNA, which was denoted as ssDNA/p-RGO/CILE and further used to hybridize with the target ssDNA sequence. Methylene blue (MB) was used as electrochemical indicator to monitor the DNA hybridization. The reduction peak current of MB after hybridization was proportional to the concentration of target A2704-12 ssDNA sequences in the range from 1.0×10−12 to 1.0×10−6 mol/L with a detection limit of 2.9×10−13 mol/L (3 σ). The electrochemical DNA biosensor was further used for the detection of PCR products of transgenic soybean with satisfactory results. [ABSTRACT FROM AUTHOR]