2022 Fiscal Year Research-status Report
Preparation and characterization of carbon nanomaterials prepared by thermal treatment of biomass DNA
| Project/Area Number |
21K12306
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| Research Institution | Nagoya University |
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Principal Investigator |
ジンチェンコ アナトーリ 名古屋大学, 環境学研究科, 准教授 (00432352)
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| Project Period (FY) |
2021-04-01 – 2024-03-31
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| Keywords | DNA / biomass / carbon nanomaterials / fluorescent nanomaterial / biodots / pyrolysis / microwave processing |
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| Outline of Annual Research Achievements |
The hydrothermal synthesis of DNA carbon nanomaterials (carbon dots) using a conventional hydrothermal reactor and the microwave reactor under the same conditions were conducted to compare the fluorescent properties of products. It was found that while the emission wavelengths were similar for both types of reaction products, the carbon dots prepared in the microwave reactor had 1.5-2-fold higher fluorescence compared to those obtained in the conventional HT heating reaction.
Next, biochars and hydrocars were prepared from DNA or DNA-derived materials by the pyrolytic treatment at 300-500 degrees and hydrolytic treatment at 200 degrees. The obtained chars were studied for their adsorption capacities towards typical environmental pollutants (heavy metal ions and pharmaceuticals) by standard batch adsorption experiments. DNA-derived biochars and hydrochars showed low adsorption capacities (ca. 1 mg/g and below) towards all studied adsorbents compared to the original DNA and DNA containing materials and standard adsorbents such as activated carbon. The decrease in the adsorption capacity during thermal treatment of DNA materials was ascribed to the decomposition of nitrogen-containing and other functional groups that served as active centers for binding with the adsorbing molecules. The application of DNA-derived chars as adsorbents was thus shown to be limited. Furthermore, it was concluded that the presence of the phosphate moieties in the DNA prevented the formation of the graphitic carbon structures suggested in the beginning of the study.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
The research has been implemented according to the original research plan for the FY2022. The comparison of hydrothermal and microwave-assisted DNA materials decomposition processes and the assessment of DNA-derived biochar and hydrochar products of DNA hydrolytic and pyrolytic decomposition was completed. The structure of thermal treatment products was clarified. Because the DNA-derived chars were found not to possess sufficiently good adsorption characteristics, the focus of the remaining part of the research project in FY2023 will be given to the fluorescent nanomaterials from DNA and methods to control properties and sensing characteristics of DNA-derived nanomaterials.
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| Strategy for Future Research Activity |
In the FY2023, hydrothermal and microwave synthesis of DNA-derived fluorescent nanomaterials will be further elaborated to control the fluorescence intensity and the emission wavelengths by admixing different nitrogen-containing reagents (urea, aliphatic and aromatic polyamines, etc.). The hydrothermal and microwave synthesis of DNA carbon dots in the presence of amines via single-step treatment of DNA - amine mixtures and two-step route of the reaction of the first prepared original DNA carbon dots with amines at the second step will be performed. In particular, while DNA-derived carbon dots obtained earlier had only blue fluorescence, amine doping will be used to prepared carbon dots with different fluorescence color. The chemical structure and fluorescent characteristics of the obtained products will be studied by UV-vis, FTIR, FS, NMR, XPS, TEM, and other standard characterization techniques. The effect of the amine-doping on ions sensing characteristics of the DNA-derived carbon nanomaterials will be systematically studied and the mechanism of this sensing will be further addressed. Finally, facile sensing methods for the analysis of heavy metal pollutants in the environmental samples will be developed.
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