6results about How to "Improve electron transfer efficiency" patented technology

The invention discloses a CSTR-based three-dimensional electrode MEC-fluidized bed reactor for anaerobic fermentation of cow dung and application, and belongs to the technical field of microbial electrochemistry. The reactor comprises a reactor main body, a feed port, a discharge port, a gas outlet and a stirring device, an anode and a cathode are arranged in the reactor main body, a conductive three-dimensional particle electrode filler is filled between the anode and the cathode to form a three-dimensional electrode system, and the anode and the cathode are connected with an external power supply. The three-dimensional electrode system is constructed, so that the reaction specific surface area and the electron transfer efficiency are greatly increased, the stimulation effect of a low-voltage electric field is amplified to the whole reaction space, and the technical bottlenecks of low mass transfer efficiency, low methane yield, easiness in system instability and the like in the traditional cow dung anaerobic digestion are solved. Compared with the traditional anaerobic digestion and two-dimensional microbial electrolysis cell, the two-dimensional microbial electrolysis cell disclosed by the invention can obviously improve the methane yield and the system operation stability, and has an excellent engineering application prospect.

The invention belongs to the technical field of biochemical engineering, and particularly relates to application of a P450 enzyme mutant and engineering bacteria thereof in synthesis of calcifediol, and the mutant is obtained by mutating one or more sites in an amino acid sequence based on a wild type P450 enzyme Vdh; the amino acid sequence of the wild type P450 enzyme Vdh corresponds to the accession number of GenBank, namely CP069288.1. Through systematic molecular dynamics simulation, conservative analysis and substrate binding pocket engineering on the Vdh enzyme, a plurality of key mutation sites are successfully screened and obtained. The constructed combined mutant (such as I144R / N173M / Q310R, Vdh-M3) shows extremely high hydroxylation activity, the pure enzyme activity of the combined mutant can reach 9.8 times that of a wild type enzyme, and the conversion rate from vitamin D3 to calcifediol is greatly increased.

This invention discloses a method for improving methanogenesis from lignocellulose based on a mixed-culture fermentation strategy, belonging to the field of anaerobic fermentation technology. The method includes the following steps: (1) inoculating activated *Trichoderma echinosporum* into a culture medium containing lignocellulose and loofah sponge as a biological carrier material for fermentation to obtain a fermentation broth; (2) activating activated sludge using a revitalizing solution; (3) inoculating the activated sludge from step (2) into the fermentation broth of *Trichoderma echinosporum* from step (1) for anaerobic fermentation to produce methanogens. This method achieves a methane yield of 262 mL / g VS, which is more than 30% higher than that of traditional anaerobic fermentation for methanogenesis, and is of great significance for improving the bioconversion of lignocellulose resources.

The invention relates to an immobilized plasma Z-type NiCuBi2O4 / Bi / NiO composite film photocatalyst as well as a preparation method and application thereof. The NiCuBi2O4 film photocatalyst is prepared by taking nickel foil as a substrate and adopting a coprecipitation method, a spin-coating method and a high-temperature calcination method. The NiCuBi2O4 / Bi thin film photocatalyst is prepared through an in-situ reduction method. And finally, preparing the plasma Z-type NiCuBi2O4 / Bi / NiO composite film photocatalyst through a sol-gel method, a spin-coating method and a high-temperature calcination method. The immobilized plasma Z-type NiCuBi2O4 / Bi / NiO composite film photocatalyst with the Ni foil as the substrate is constructed aiming at the problems of agglomeration and recovery in powder photocatalyst reaction, non-noble metal Bi nano particles are introduced to serve as conductive channels, the low-cost plasma resonance effect is achieved, the enhanced catalytic degradation activity is obtained under sunlight, and the photocatalytic degradation effect is improved. Meanwhile, the practical problem that precious metal depends on and powder catalysts are difficult to separate and recover is solved.

The invention belongs to the technical field of electrochemical sensors, and relates to a perfluorinated compound electrochemical sensor based on a two-parameter molecular imprinting composite coating as well as a preparation method and application of the perfluorinated compound electrochemical sensor. The perfluorinated compound electrochemical sensor comprises a PFOA molecular imprinting sensing area, a PFOS molecular imprinting sensing area, a glass substrate, a circuit board, an external electrode and the like. [Fe (CN) 6] < 3- / 4-> is taken as a probe molecule, the hole effect on a molecularly imprinted membrane is utilized, that is, a target molecule can be adsorbed to a binding site through electrostatic attraction or hydrogen-bond interaction, after the originally exposed binding site is occupied by the target molecule, the surface conductivity of an electrode is inhibited, a relatively low signal response is generated, and the detection sensitivity is improved. And the concentrations of PFOA and PFOS are quantified according to the change of a current signal generated on the surface of the working electrode. The electrochemical sensor disclosed by the invention is successfully applied to detection of PFOA and PFOS in a water sample, has the advantages of rapid response, high sensitivity, strong specificity, good stability and good anti-interference performance, and can realize simultaneous detection of double targets (PFOA and PFOS) and in-situ cleaning of the electrode in one set of sensor; the volume of the needed sample is obviously reduced, tedious and repeated manual operation is reduced, the cost is low, carrying is easy, the requirement for on-site rapid detection of the actual sample can be met, and marketization is more convenient.

The application provides an electrochemical aptamer sensor for detecting streptomycin and a preparation method thereof, and the preparation method comprises the following steps: S1, pretreating a glassy carbon electrode; S2, preparing Cu-ZIF-8@AuNPs; performing nitrogen plasma treatment on the Cu-ZIF-8@AuNPs; S3, dropping the plasma modified Cu-ZIF-8@AuNPs suspension on the pretreated glassy carbon electrode and drying; S4, modifying the plasma modified Cu-ZIF-8@AuNPs / GCE composite electrode by using streptomycin aptamer to obtain a modified electrode; S5, performing blocking treatment by using BSA, and then performing washing and drying to obtain the electrochemical aptamer sensor; the plasma modified Cu-ZIF-8@AuNPs can significantly improve the electron transfer efficiency, and can enhance the streptomycin detection sensitivity, selectivity and stability of the electrochemical aptamer sensor.