A novel Ni₃N/graphene nanocomposite has been synthesized as pseudo supercapacitor electrode material with high capacitance and energy density, due to its unique two-step oxidation/reduction reaction mechanism.

3–8 nm sized high quality graphene quantum dots with zigzag edges and multi-heteroatom doping were synthesized through a green process of electrochemically cutting pristine few-layer graphene flakes. The graphene quantum dots exhibit the structural features of monodisperse and shaped nanocrystals co-doped by O, N and F elements or chemical groups mainly at the zigzag edges. The cutting and in situ doping of the graphene flakes into dots were realized in the potential/current exchangeable electrochemical etching process without any thermal treatment. It was found that the graphene dots showed high electrocatalytic activity for the oxygen reduction reaction including 70 times enhancement in voltammetric current in oxygen saturated KOH compared to that in nitrogen. In addition, low in vitro cytotoxicity and fluorescent labeling to Vero cells and NRK cells of the graphene dots were presented. The Gdots synthesized may potentially be applied in the fields of electrocatalysis and biomedicine.

The influence of oxidation and esterification on the ester balance of aged Baijiu and methodology for the rational design of liquor flavors to optimize the practice of Baijiu production are not completely understood. We investigated the influence of ester balance on the flavor compounds of aged Baijiu by conducting constituent analysis of Baijiu from different aging times (0, 1, 2, 3, 4, 5, and 10 years). The changes of the main flavor compounds in the aging process were determined, and the correlations among different chemical reactions, such as oxidation, hydrolysis, and esterification, were systematically expounded. Furthermore, cluster analysis of the heat map indicated significant differences between aged Baijiu and new Baijiu and recommended a suitable aging time of 2–3 years.

A label-free electrochemical DNA sensor was fabricated by deposition of polyaniline and pristine graphene nanosheet (P/G_ratios) composites in different mass ratios, DNA probe and bovine serum albumin (BSA) layer by layer on the surface of a glassy carbon electrode (GCE). Electrochemical impedance spectroscopy (EIS) was employed to monitor every step of fabrication of P/G_ratio-based DNA sensors and to evaluate the detection results in terms of the hybridization of complementary DNA, mutant DNA and non-complementary DNA. The results illustrate that the P/G_ratio-based DNA sensor could highly efficiently detect complementary DNA from 0.01 pm to 1 μm and discriminate single-nucleotide polymorphisms (SNPs). In the process of detection, double-stranded DNA (dsDNA), resulting from hybridization of a DNA probe, escaping from or remaining on the sensor surface, was monitored by changing the ratio of polyaniline (PANI) to graphene, which was decided by the competition between the electrostatic interaction and Brownian motion.