Display of Glucose Oxidase on Bacillus subtilis Spore Surface and Its Application in Electrode
Wenhu Chen,
Runlong Ma,
Ping Lin,
Haibo Yuan,
Hongling Liu,
Yi Jiang,
Di Huang,
Yaohong Ma,
Tengfei Wang
Issue:
Volume 7, Issue 2, June 2022
Pages:
34-47
Received:
12 March 2022
Accepted:
30 March 2022
Published:
8 April 2022
DOI:
10.11648/j.wjac.20220702.11
Downloads:
Views:
Abstract: Glucose oxidase (GOD) is widely used in the fields of food, chemistry and medicine due to its specific catalytic activity, and it is the main tool enzyme in the biological field. The biological preparation of GOD can be realized by the method of surface display on Bacillus subtilis spores. In this study, we analyzed the display characteristics of eleven cot proteins on the spore coat and determined the fluorescence intensity of different spore coat proteins by flow cytometry as follows: CotX > CotY > CotF > CotC > CotE > CotG > CotV > CotB > CotM > CotA > CotW. Next, CotC, CotX and CotY were selected to display GOD on the surface of spores, and CotX demonstrated the highest GOD activity. Subsequently, graphene oxide was added to the glassy carbon electrode and prussian blue was deposited, the surface of this electrode was fixed with spore–GOD and finally covered with a layer of Nafion solution to prepare glucose detection electrode. In the range of 0.1-7.0 mmol/L glucose, the cyclic voltammetry curve on the enzyme electrode showed a linear relationship with the glucose concentration. The calibration curve equation was I = 1.3047Cglucose + 3.639 (R2 = 0.9929), and its detection limit was 7.5 μmol/L (S/N = 3). This modified electrode has good conductivity, stability, reproducibility and can be used for the analysis and determination of glucose.
Abstract: Glucose oxidase (GOD) is widely used in the fields of food, chemistry and medicine due to its specific catalytic activity, and it is the main tool enzyme in the biological field. The biological preparation of GOD can be realized by the method of surface display on Bacillus subtilis spores. In this study, we analyzed the display characteristics of e...
Show More
TPhPFe3+/Al2O3//Al Biomimetic Sensor of Catalase and Peroxidase Type
Malikova Nurana Nahmad,
Ali-zadeh Nahmad Islam,
Nagiev Tofik Murtuza
Issue:
Volume 7, Issue 2, June 2022
Pages:
48-53
Received:
26 April 2022
Accepted:
17 May 2022
Published:
20 June 2022
DOI:
10.11648/j.wjac.20220702.12
Downloads:
Views:
Abstract: Rapid and accurate determination of hydrogen peroxide is very essential, as it is not only a product of reactions catalyzed by a number of infinitely selective oxidases, but also a cardinal combined element of food, pharmaceutical and environmental developments. Among the methods used for analysis of hydrogen peroxide, such as titrimetry, photometry, chemiluminescence, high-performance liquid electrochromatography and electrochemistry, enzyme-based biosensors attract important attention, due to the fact that this class of methods is characterized by sensitivity, convenience and high selectivity. Another, no less important aspect is related to determination of microquantities of C2H5OH in aqueous media of various origins. The need to develop express methods for determining the concentration of C2H5OH in aqueous solutions follows from the demand for the quality of alcohol products. As is known, the taste and drinking qualities of the product depend on the ratio of methyl and ethyl alcohols. In this aspect, we have carried out a research on the development of a biomimetic sensor of the catalase and peroxidase type for determining trace amounts of hydrogen peroxide in aqueous and aqueous-alcoholic solutions, as well as determining low concentrations of ethyl alcohol in an aqueous solution. The physicochemical features of catalase and peroxidase biomimetic sensors were studied by potentiometric research works, where metals were used as a transducer. Created on the basis of smart biomimetic material (iron tetraphenylporphyrin) and metals, the biomimetic sensor is characterized by long-term stability, highest sensitivity and reproducibility, with the possibility of expanding the range of detectable trace concentrations of H2O2 and C2H5OH in an aqueous solution. As a result of the study carried out, it was found that the developed TPhPFe3+/Al2O3//Al biomimetic sensors of the catalase and peroxidase types have a sensitivity threshold of 10-6 wt.% and 10-4 wt.%, respectively.
Abstract: Rapid and accurate determination of hydrogen peroxide is very essential, as it is not only a product of reactions catalyzed by a number of infinitely selective oxidases, but also a cardinal combined element of food, pharmaceutical and environmental developments. Among the methods used for analysis of hydrogen peroxide, such as titrimetry, photometr...
Show More
