Qiufang Yao,Hanwei Wang,Chao Wang,Chunde Jin,Qingfeng Sun
Bradyrhizobium japonicum (BJ), which has a symbiotic relationship with soybean roots, possessed an abundant three-dimensional (3D) structure with a high N content. A soybean leaf (SL) with a hierarchically ordered macroporous network and numerous polar hydroxyl groups was proposed as a separator for a supercapacitor. A 3D hierarchical porous carbon was prepared by the facile carbonization with chemical activation of BJ. The as-prepared material possesses a large specific surface area (1275 m2·g–1), unique 3D hierarchical porosity, and good electrical conductivity. The electrochemical performance of the Bradyrhizobium japonicum-derived porous carbons at a mass ratio of 1.5 (ZnCl2/BJ = 1.5) (BJPC-1.5) for supercapacitors with a SL separator showed a high capacitance (358 F/g at 1 A·g–1), a superior cycle stability of 91% over 8000 cycles, and a superior rate capability in a symmetric two-electrode supercapacitor in 6 M KOH. Furthermore, the electrochemical performance of the BJPC-1.5 with a SL separator was comparable to that with the commercialized cellulose and polypropylene (PP) separators. More attractively, the SL separator with a preferable water uptake showed a much better performance in the BJPC-1.5 cell than the PP separator. These results provide an insight into the full usage of a natural and biodegradable biomass for separator and electrode materials for a supercapacitor.
Soybean mosaic virus (SMV) is the most prevalent viral pathogen of soybean worldwide that reduces seed quality and causes serious losses in yields. The accurate, rapid and early detection of SMV strains is crucial for screening SMV-resistant soybean varieties and controlling soybean mosaic disease timely. In this study, we report a loop-mediated isothermal amplification (LAMP) assay for visual and rapid detection of SMV-SC7, the major prevalent SMV strain in China, in soybean leaves. Specific primers were rationally designed and tested to detect the SMV-SC7 strain. The detection limit for SMV-SC7 can be as low as 10 −4 ng/μL by the developed LAMP assay. These results were visualized by three indicators (SYBR green I, neutral red and hydroxy naphthol blue) with high fidelity. The high analytical performance of the LAMP assay was demonstrated with 21 soybean cultivars, among which 8 soybean cultivars were further inoculated with consistent results to those achieved by LAMP. This visual and rapid LAMP assay is highly promising for early detection of SMV-SC7-associated plant diseases.