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In this paper, using molybdenum disulfide doped with gold nanoclusters (Au NCs@MoS2) as the substrate, an aflatoxin aptamer sensor was constructed utilizing iron porphyrin organic porous material modified with streptavidin and loaded with gold nano-bipyramids (SA-Au NBPs@ porous aromatic framework (PAF)-40-Fe) as a label. The catalyzed reduction current of hydrogen peroxide (H2O2) by Au NBPs@PAF-40-Fe was detected which is proportional to the concentration of aflatoxin B1. Thereby, quantitative detection of aflatoxin B1 (AFB1) is achieved. Under the optimal conditions, the linear range of the sensor is 0.05 ~ 85 ng/mL with detection limit of 0.017 ng/mL and the linear correlation coefficient (R2) of 0.9825. The average recovery is 99.28 %. This aflatoxin aptamer sensor has good selectivity and provides a highly sensitive method for the detection of aflatoxin.

In our previous work, a thrombin-like enzyme (TLE), agkihpin, was successfully isolated, purified, cloned and named from the venom of Gloydius halys Pallas, having fibrinolytic, fibrinogenolytic and thrombosis-reduced activities, attenuating migration of liver cancer cell, and without bleeding risk. To explore the possibility of agkihpin as a thrombolytic and/or anti-metastasis agent in the future, in this study recombinant agkihpin was expressed and purified in Escherichia coli, and its biological activities investigated. Thus, r-agkihpin-2 was successfully expressed and purified and confirmed by Western blot and peptide mass fingerprinting. After purification and renaturation, 46 mg (399 U) of active r-agkihpin-2 was obtained from 1 L bacterial culture. The results of the arginine esterase activity assay, fibrin plate test fibrinogenolytic activity assay, thrombin-induced venous thrombosis assay, Scratch-Wound assay and bleeding assay showed that active r-agkihpin-2 had slightly lower TAME hydrolytic, fibrinolytic, fibrinogenolytic, thrombus-reduced and migration-attenuated activities than those of native agkihpin, and had no bleeding risk. These findings confirmed that, active r-agkihpin-2 could be further investigated for thrombolytic and/or anti-metastasis drug discovery in the future.

Dicyclohexyldithiophosphinic acid was synthesized by a three-step strategy through the Grignard reaction of PSCl3 with cyclo-C6H11MgBr and the P-P bond-cleavage reaction of the intermediate. The 1H NMR data of ammonium dicyclohexyldithiophosphinate 4 and dicyclohexyldithiophosphinic acid 5 were characterized by 1H-1H correlation spectra.