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Supercapacitors are promising energy storage devices in terms of power density and lifetime. Organic electrolytes are frequently applied in commercial supercapacitor devices. However, their water‐based counterparts are much safer, more sustainable and cost‐effective. In this study we therefore present, for the first time, aqueous tartrate‐based electrolytes (sodium tartrate / ammonium tartrate) for supercapacitor applications, and relate them to well‐known inorganic aqueous electrolytes like Na2SO4. Additionally, the influence of the cation on the electrochemical performance of supercapacitors is investigated using sodium and ammonium cations for comparison. We demonstrate the electrochemical performance and physicochemical properties of ammonium tartrate / sulfate and sodium tartrate / sulfate. An improvement of the conductivity in the range of 40–60 % was achieved by the exchange of sodium cation with ammonium cation. Carbon electrodes in newly introduced aqueous tartrate‐based electrolytes deliver high specific capacitances up to 117 Fg−1. Furthermore, electrical double layer capacitors (EDLCs) containing 1 M ammonium tartrate display a high energy density at 0.1 Ag−1 and at 10 Ag−1 (9.88 Whkg−1 and 1.14 Whkg−1, respectively). Floating tests show excellent long‐term performance. Tartrate‐based EDLCs retain >80 % of their initial capacitance at 1.6 V cell voltage (120 h floating time). In the case of ammonium tartrate electrolyte, a novel metal‐free and non‐toxic concept for an eco‐friendly supercapacitor device is proposed. [ABSTRACT FROM AUTHOR]

Due to the high power density, fast charging speed, and long cycling stability, supercapacitors have been developed rapidly in the area of electrical energy storage devices in the past decades. During the application of supercapacitors, it was found that the properties of the electrode material can greatly affect the supercapacitor performance. Recently, electrode materials based on polymer waste‐derived carbon materials (PWCM) have attracted much attention because of the low preparation cost, good electrode performance, and great benefits for environmental protection. This review aims to describe the recent research development and summarize the investigation state in the field of the PWCM electrodes prepared from polyethylene, polypropylene, polyethylene terephthalate, polystyrene, etc. The preparation method and the electrode performance of the PWCM electrodes are compared. The relationship among the preparation methods, material structure, and electrochemical performance of the PWCM electrodes was explored. Furthermore, the prospects for the application of the PWCMs were provided. [ABSTRACT FROM AUTHOR]

Uric acid (UA) is a blood and urine component obtained as a metabolic by‐product of purine nucleotides. Abnormalities in UA metabolism cause crystal deposition as monosodium urate and lead to various diseases such as gout, hyperuricemia, Lesch–Nyhan syndrome, etc. Monitoring these diseases requires a rapid, sensitive, selective, and portable detection approach. Therefore, this study demonstrates the hydrothermal synthesis of CuFe2O4/reduced graphene oxide (rGO) nanocomposite for selective detection of UA. After the nanocomposite synthesis, characterization was performed by X‐ray diffraction spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, X‐ray photoelectron spectroscopy, UV–visible spectrometry, atomic force spectroscopy, scanning electron microscopy, and electrochemical analysis. Furthermore, from the electrochemical analysis using cyclic voltammetry (CV), kinetic studies were carried out by varying the scan rate to obtain the diffusion coefficient, surface concentration, and rate of charge transfer to achieve a calibration curve that indicates the quasi reversible nature of the fabricated electrode with a linear regression coefficient of oxidation (R2: 0.9992) and reduction (R2: 0.9971) peaks. Moreover, the fabricated nonenzymatic amperometric sensor to detect UA with a linearity (R2: 0.9989) of 1–400 μM was highly sensitive (2.75 × 10−4 mAμM−1 cm−2) and had a lower limit of detection (0.01231 μM) at pH 7.5 in phosphate‐buffered saline solution. Therefore, the CuFe2O4/rGO/ITO‐based nonenzymatic sensor could detect interfering agents and spiked real bovine serum samples with higher sensitivity and selectivity for UA detection. [ABSTRACT FROM AUTHOR]

Growing environmental and health demands along with the deficiency of conventional energy sources result in the need for alternative solutions in the field of energy storage and analyte detecting systems. To address these issues, a significant increase in research interest for novel composite materials has been observed in recent years. Conductive polymers and graphene‐based composites have emerged as promising electrode materials for supercapacitors and electrochemical sensors due to their improved electrochemical properties and versatility of the synthesis methods. The synergistic effect between the composite components and the unique morphology, physical and chemical characteristics result in enhanced performance of the electrochemical devices. In this review, we discuss recent trends and achievements in the synthesis, nanoarchitecture, and application of conductive polymers and graphene‐based composites in the field of supercapacitors and electrochemical sensors. Finally, the remaining challenges and future perspectives are discussed. It is believed that this review will provide a current summary and new inspiration for groundbreaking research on advanced electrochemical devices. [ABSTRACT FROM AUTHOR]

An electrochemical study of the fungicide bixafen using a paste electrode based on thermally reduced graphene oxide (TRGOPE) synthesized in air is presented for the first time. Cyclic voltammetry and square‐wave voltammetry (SWV) were conducted to characterize the mechanism of the underlying electrode process of bixafen. Optimization of the procedure for the quantitative determination of bixafen was carried out by SWV. Excellent electroanalytical performance in terms of a limit of detection of 31.5 nmol L−1 was achieved. The TRGOPE was effectively employed to analyze bixafen in spiked river and tap water samples. The selectivity towards bixafen determination was also assessed. [ABSTRACT FROM AUTHOR]

Camera or genetic data are increasingly used to estimate wildlife abundance and density. We integrated video camera data with genetic data over 7 years to estimate annual age‐structured apparent survival of American black bears (Ursus americanus). We identified 70 individuals through meticulous scrutiny of 7531 video captures, cross‐referenced with 721 genetic captures from hair samples concurrently collected from stations in view of cameras. We used the Cormack–Jolly–Seber model in Program Mark to estimate annual age‐structured apparent survival for yearling males, yearling females, 2+ year‐old males, and 2+ year‐old females. We manually calculated cub survival. We compared parameter estimates based on combined video and genetic data with those based on only genetic data. Combining video and genetic data provided a means to test video‐based identification accuracy, which was highest for females (97%–100%). Annual apparent survival was highest for yearling females (φ = 0.92, SE = 0.07), followed by 2+ year‐old females (φ = 0.88, SE = 0.05), 2+ year‐old males (φ = 0.84, SE = 0.06), and yearling males (φ = 0.80, SE = 0.14). Annual cub survival (φ = 0.86, SE = 0.07) was likely biased because we could not account for mortality that occurred in‐den through early spring. Annual apparent survival and recapture probabilities derived from only genetic data were lower than those derived from combined video and genetic data. Our finding that noninvasive data can be used to estimate annual age‐structured apparent survival of a species with relatively indistinct traits is broadly relevant to wildlife research and conservation. [ABSTRACT FROM AUTHOR]

Simultaneous analysis of ascorbic acid (AA), uric acid (UA), and dopamine (DA) is desirable as they are important biomarkers that coexist in biological fluids. Electrochemical detection of these molecules can be challenging as their oxidation peaks are poorly resolved at most unmodified electrodes. Modifications are typically necessary for analysis which increase cost and complicate fabrication. Herein, inexpensive and moldable polystyrene thermoplastic electrodes (PS TPEs), that can be used for simultaneous analysis of AA, DA, and UA, without surface modification, were presented. Electrode composition was optimized for conductivity, capacitance, and electrochemistry. Detection limits were 4, 0.9, and 4 μm for AA, DA and UA respectively. PS TPEs were also challenged in urine; excellent recoveries (90–110 %) were seen for AA and UA. DA showed lower recoveries (82 % for 10 μm and 47 % for 5 μm), but in the future, higher recoveries can be achieved through design considerations and further material optimization. [ABSTRACT FROM AUTHOR]

Dopamine (DA) is an important neurotransmitter, which is created and released from the central nervous system. It plays a crucial role in human activities, like cognition, emotions, and response to anything. Maladjustment of DA in human blood serum results in different neural diseases, like Parkinson's and Schizophrenia. Consequently, researchers have started working on DA detection in blood serum, which is undoubtedly a hot research area. Electrochemical sensing techniques are more promising to detect DA in real samples. However, utilizing conventional electrodes for selective determination of DA encounters numerous problems due to the coexistence of other materials, such as uric acid and ascorbic acid, which have an oxidation potential close to DA. To overcome such problems, researchers have put their focus on the modification of bare electrodes. The aim of this review is to present recent advances in modifications of most used bare electrodes with carbonaceous materials, especially graphene, its derivatives, and carbon nanotubes, for electrochemical detection of DA. A brief discussion about the mechanistic phenomena at the electrode interface has also been included in this review. [ABSTRACT FROM AUTHOR]

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Individual identification was assessed for 30 brown bears (Ursus arctos) from the endangered Apennine population in central Italy, mostly through non-invasive sampling. Shed hairs were used as a source of DNA to obtain single genotype profiling at 12 microsatellite loci. Average expected heterozygosity (0.438) and mean number of alleles per locus (2.2) showed that the level of genetic diversity was one of the lowest recorded for brown bear populations across their European and North American ranges. A large portion of the original genetic variation may have been lost through random genetic drift during the recent period of isolation. The level of genetic variability proved sufficient to identify the bears individually by using nine microsatellite loci. The probability that two animals shared by chance the same multilocus genotype was estimated to be 1 in 100. Despite the recent history of small population size, the average relatedness indicated that the majority of individuals are not first-order relatives. Simulated paternity tests showed that a 12-loci genotype may be necessary to assign paternity with an 80–95% confidence level. Lack of genetic diversity, as well as the maintenance of an adequately effective number, may seriously jeopardise the long-term survival of this population. Furthermore, high mortality rates, poaching and encroachment by human activities represent immediate, urgent concerns. A population increase through enforced protection and habitat restoration is recommended. Presently, restocking with bears from other source populations should be discouraged to avoid genetic extinction. Non-invasive sampling provided reliable population and individual genetic data. Microsatellite genotyping proved a valuable genetic tagging method and a feasible alternative to conventional field counts for the brown bear in central Italy. [ABSTRACT FROM AUTHOR]