Simple Semiempirical Method for the Location Determination of HOMO and LUMO of Carbon Dots

2021 ◽  
Author(s):  
Kaiqiang Wei ◽  
Fan Liao ◽  
Hui Huang ◽  
Mingwang Shao ◽  
Haiping Lin ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Semiempirical Method ◽  
Location Determination ◽  
Homo And Lumo

Semiempirical Method MNDO for the Evaluation of the Effect of Different Substituents at the Imine-Carbon Position on the Acetaldemine-Vinylamine Tauotomerization and Comparison to the Substitution at α-Position

2004 ◽  
Vol 59 (12) ◽  
pp. 987-996
Author(s):  
Hamzeh S. M. Al-Omari
Keyword(s):  
Free Energy ◽  
Charge Distribution ◽  
Energy Gap ◽  
Semiempirical Method ◽  
Free Energy Change ◽  
Isodesmic Reactions ◽  
Mndo Calculations ◽  
Homo And Lumo ◽  
Resonance Stabilization

MNDO calculations have been employed to study the effect of some substituents of the acetaldemine-vinylamine tautomeric system at the imine-carbon position of CH3CXNH, where X = H, F, CN, NH2, NO2, BH2, CH3 and CF3. It is found that the substitutents F, NH2 and NO2 encourage the formation of the enamine tautomer. The substitutents CN, CH3, CF3 and BH2 encourage the formation of the imine tautomer. Isodesmic reactions, free energy change (ΔG), charge distribution and energy gap (Eg) between HOMO and LUMO were used to prove these findings. Resonance stabilization was a major factor in the determination of the most stable tautomer. These results were compared with previous work on the substitution at the σ -carbon position.

Carbon dots derived from Fusobacterium nucleatum for intracellular determination of Fe3+ and bioimaging both in vitro and in vivo

2021 ◽  
Author(s):  
Lijuan Liu ◽  
Shengting Zhang ◽  
Xiaodan Zheng ◽  
Hongmei Li ◽  
Qi Chen ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Fusobacterium Nucleatum ◽  
Living Cells ◽  
First Time ◽  
Fluorescent Carbon Dots ◽  
Fluorescent Carbon

Fusobacterium nucleatum has been employed for the first time to synthesize fluorescent carbon dots which could be applied for the determination of Fe3+ ions in living cells and bioimaging in vitro and in vivo with excellent biocompatibility.

Nitrogen-doped carbon dots for dual-wavelength excitation fluorimetric assay for ratiometric determination of phosalone

2021 ◽  
Vol 188 (8) ◽  
Author(s):  
Xiufen Liao ◽  
Congjin Chen ◽  
Jielun Yang ◽  
Ruxia Zhou ◽  
Lulu Si ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Dual Wavelength ◽  
Nitrogen Doped ◽  
Fluorimetric Assay ◽  
Doped Carbon Dots ◽  
Nitrogen Doped Carbon

scholarly journals Synthesis of Fluorescent Carbon Dots and Their Application in Ascorbic Acid Detection

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1246
Author(s):  
Tengfei Wang ◽  
Hui Luo ◽  
Xu Jing ◽  
Jiali Yang ◽  
Meijun Huo ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Fluorescence Intensity ◽  
Carbon Dots ◽  
Ph Dependence ◽  
Scale Up ◽  
Water Soluble ◽  
Jujube Fruit ◽  
Fluorescent Carbon Dots ◽  
Fluorescent Carbon

Water-soluble fluorescent carbon dots (CDs) were synthesized by a hydrothermal method using citric acid as the carbon source and ethylenediamine as the nitrogen source. The repeated and scale-up synthetic experiments were carried out to explore the feasibility of macroscopic preparation of CDs. The CDs/Fe3+ composite was prepared by the interaction of the CDs solution and Fe3+ solution. The optical properties, pH dependence and stability behavior of CDs or the CDs/Fe3+ composite were studied by ultraviolet spectroscopy and fluorescence spectroscopy. Following the principles of fluorescence quenching after the addition of Fe3+ and then the fluorescence recovery after the addition of asorbic acid, the fluorescence intensity of the carbon dots was measured at λex = 360 nm, λem = 460 nm. The content of ascorbic acid was calculated by quantitative analysis of the changing fluorescence intensity. The CDs/Fe3+ composite was applied to the determination of different active molecules, and it was found that the composite had specific recognition of ascorbic acid and showed an excellent linear relationship in 5.0–350.0 μmol·L−1. Moreover, the detection limit was 3.11 μmol·L−1. Satisfactory results were achieved when the method was applied to the ascorbic acid determination in jujube fruit. The fluorescent carbon dots composites prepared in this study may have broad application prospects in a rapid, sensitive and trace determination of ascorbic acid content during food processing.

Chitosan-derived N-doped carbon dots for fluorescent determination of nitrite and bacteria imaging

2021 ◽  
Vol 251 ◽  
pp. 119468
Author(s):  
Lili Sun ◽  
Hongmei Zhang ◽  
Yesheng Wang ◽  
Zhong Xiong ◽  
Xihui Zhao ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Doped Carbon Dots
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