Wei Zhang

Sodium-ion batteries (SIBs) are regarded as promising alternatives to lithium-ion batteries (LIBs) in the field of energy, especially in large-scale energy storage systems. Tremendous effort has been put into the electrode research of SIBs, and hard carbon (HC) stands out among the anode materials due to its advantages in cost, resource, industrial processes, and safety. However, different from the application of graphite in LIBs, HC, as a disordered carbon material, leaves more to be completely comprehended about its sodium storage mechanism, and there is still plenty of room for improvement in its capacity, rate performance and cycling performance. This paper reviews the research reports on HC materials in recent years, especially the research process of the sodium storage mechanism and the modification and optimization of HC materials. Finally, the review summarizes the sterling achievements and the challenges on the basis of recent progress, as well as the prospects on the development of HC anode materials in SIBs.

Being able to uniquely produce both a reductant and oxidant, thiourea dioxide has been exploited to detect carbonyl compounds by reduction for the first time.

Chemiluminescence of indigo carmine/glucose/hemin/H ₂ O ₂ has been reported for the first time, and used for sensitive non-enzymatic detection of glucose and indigo carmine.

Alkaline phosphatase (ALP) is one of the most used enzymes for the diagnosis and monitoring of many diseases. This can be achieved by either detecting ALP as a biomarker or using ALP as the label of enzyme-linked bioassays. ALP-based electrochemical sensors have been considered as promising tools in biosensor devices for POCT systems thanks to their high sensitivity and selectivity, low cost, ease of use, portability, simplicity of construction and excellent compatibility with miniaturization technologies. These electrochemical sensors can be used for the diagnosis of different diseases such as cancers, hormonal diseases, bacterial diseases, etc. via the detection of ALP as a biomarker or other biomarkers using ALP as the label. This review summarizes some of the recent advances related to ALP-based electrochemical sensors for the diagnosis and monitoring of diseases between 2016 and 2018.

This review examines the current status (from 2016 to December 2018) of the electroanalytical application of boron-doped diamond (BDD), in view of its advantages and challenges for electroanalytical applications. The effect of the boron-doping level, sp³/sp² ratio, and BDD surface termination on the electrochemical properties of BDD electrodes is discussed. The most interesting and significant developments concerning the electrochemical oxidation and reduction of chemical substances onto BDD in single and multi-analyte modes, the beneficial role of surfactants in BDD electrode-based electroanalysis, surface modifications, modification of electrode surfaces with metal nanoparticles, porous BDD surfaces, and the specificity of BDDEs in the microfluidic context, are considered. Basic information on the electroanalysis of organic substances in single- and multi-analyte detection modes is given in the tables. Other non-common electroanalytical applications of BDD, such as BDD as an electrode material for electrogenerated electrochemiluminescence, and BDD for in vivo on-line determination of analytes, detecting bio-potential changes in plants, and pH and gas sensing, are presented.

The authors describe the first chemiluminescence (CL) based method for determination of pyridoxal 5′-phosphate (PLP). PLP is found to generate intense CL with lucigenin higher than that of the conventional lucigenin-H₂O₂ system by a factor of about 9.0. This new finding is used to be in a detection method for PLP via flow injection analysis (FIA). Response is linear in the 50 nM to 200 μM PLP concentration range with a correlation coefficient of 0.998, and the detection limit (at an S/N of 3) is 6.9 nM. The assay is highly selective over various amino acids, vitamins, sugars, coenzymes and metal ions cofactors. It exhibits advantages over the commonly employed HPLC methods in that it is rapid, more economic, eco-friendly and high throughput FIA detection of PLP without the need for toxic derivatization reagents, organic solvents, and HPLC instrumentation. The method was successfully applied to the determination of PLP in (spiked) human blood samples with recoveries in the range from 96.2–101.6% with % RSD < 4.0. The new system is also employed to determine lucigenin in the linear range of 0.3 to 100.0 μM with a correlation coefficient of 0.994 and the limit of detection is 0.04 μM. Schematic of the chemiluminescent assay for pyridoxal 5′-phosphate (PLP). Lucigenin−PLP demonstrates 9-fold stronger chemiluminescence intensity than the lucigenin−H₂O₂ system. The detection limit of PLP is 6.9 nM. The method can detect PLP in human serum with good recoveries.

H₂O₂ is frequently used at high concentrations in various applications. It is very challenging to detect high concentrations of H₂O₂ and to eliminate oxygen interference for H₂O₂ detection through electrochemical reduction. In the present investigation, the electrochemistry of H₂O₂ at stainless steel electrode has been carried out for the first time. A cathodic peak for H₂O₂ reduction was observed at about −0.40 V, and no cathodic peak for dissolved oxygen reduction was observed on type 304 stainless steel electrode. Amperometric determination of H₂O₂ on type 304 stainless steel electrode displayed a linear range from 0.05 up to 733 mM with a detection limit of 0.02 mM (S/N = 3) and a sensitivity of 16.7 μA mM^–1 cm^–2. The type 304 stainless steel electrode not only shows much higher upper limit than other reported electrodes for the detection of concentrated H₂O₂ but also is free from oxygen interference, which is of great importance for practical applications. This method could detect H₂O₂ in wound wash and lake water with excellent recoveries. Moreover, we successfully applied the stainless steel electrode to determine glucose using glucose oxidase to catalyze the oxidation of glucose to generate hydrogen peroxide. The linear range for glucose is between 0.5 and 25 mM, which covers clinically important blood glucose concentrations well.