Chirality Inversion on the Carbon Dot Surface via Covalent Surface Conjugation of Cyclic α-Amino Acid Capping Agents

2018 ◽  
Vol 29 (11) ◽  
pp. 3913-3922 ◽  
Author(s):  
Fatemeh Ostadhossein ◽  
Gururaja Vulugundam ◽  
Santosh K. Misra ◽  
Indrajit Srivastava ◽  
Dipanjan Pan
Keyword(s):  
2020 ◽  
Vol 16 (1) ◽  
pp. 71-78 ◽  
Author(s):  
Ravi Arunan ◽  
Printo Joseph ◽  
Muthusamy Sivakumar ◽  
Suthanthira Cross Guevara Kiruba Daniel

Background: Mn doped ZnS is selected as the right element which is prominent among quantum dot for its high luminescent and quantum yield property and also non toxicity while comparing with other organometallic quantum dot synthesized by using different capping agents. Methods: An interesting observation based on colorimetric sensing of dopamine using manganese doped zinc sulfide quantum dot is discussed in this study. Mn doped ZnS quantum dot surface passivated with capping agents such as L-histidine and also in polymers like chitosan, PVA and PVP were studied and compared. The tunable fluorescence effect was also observed in different polymers and amino acid as capping agents. Optical characterization studies like UV-Visible spectroscopy and PL spectroscopy have been carried out. The functional group modification of Quantum dot has been analyzed using FTIR and size and shape analysis was conducted by using HRTEM image. Result: The strong and broad peak of FTIR in the range of 3500-3300 cm-1 confirms the presence of O-H bond. It is also observed that quenching phenomena in the luminescent peak are due to weaker confinement effect. The average size of the particle is shown to be around 4-5 nm. Changes in color of the quantum dot solution from transparent to dark brown has been due to the interaction with dopamine. Conclusion: Finally, L-Histidine amino acid capped Mn:ZnS shows better results in luminescence and size confinement properties. Hence, it was chosen for dopamine sensing due to its colloidal nature and inborn affinity towards dopamine, a neurotransmitter which is essential for early diagnosis of neural diseases


2021 ◽  
Author(s):  
Jason V Rowley ◽  
Patrick Wall ◽  
Huayang Yu ◽  
Mark J Howard ◽  
Daniel Baker ◽  
...  

Polymer-coated carbon dot-containing calcium carbonate nanoparticles are reported as unique nanocomposites capable of encapsulating a chemotherapeutic drug and displaying afterglow behaviour. The poly(amino acid) polymeric component enhances nanoparticle dispersion and...


Author(s):  
M.K. Lamvik ◽  
L.L. Klatt

Tropomyosin paracrystals have been used extensively as test specimens and magnification standards due to their clear periodic banding patterns. The paracrystal type discovered by Ohtsuki1 has been of particular interest as a test of unstained specimens because of alternating bands that differ by 50% in mass thickness. While producing specimens of this type, we came across a new paracrystal form. Since this new form displays aligned tropomyosin molecules without the overlaps that are characteristic of the Ohtsuki-type paracrystal, it presents a staining pattern that corresponds to the amino acid sequence of the molecule.


Author(s):  
A. J. Tousimis

The elemental composition of amino acids is similar to that of the major structural components of the epithelial cells of the small intestine and other tissues. Therefore, their subcellular localization and concentration measurements are not possible by x-ray microanalysis. Radioactive isotope labeling: I131-tyrosine, Se75-methionine and S35-methionine have been successfully employed in numerous absorption and transport studies. The latter two have been utilized both in vitro and vivo, with similar results in the hamster and human small intestine. Non-radioactive Selenomethionine, since its absorption/transport behavior is assumed to be the same as that of Se75- methionine and S75-methionine could serve as a compound tracer for this amino acid.


Author(s):  
Chi-Ming Wei ◽  
Margaret Hukee ◽  
Christopher G.A. McGregor ◽  
John C. Burnett

C-type natriuretic peptide (CNP) is a newly identified peptide that is structurally related to atrial (ANP) and brain natriuretic peptide (BNP). CNP exists as a 22-amino acid peptide and like ANP and BNP has a 17-amino acid ring formed by a disulfide bond. Unlike these two previously identified cardiac peptides, CNP lacks the COOH-terminal amino acid extension from the ring structure. ANP, BNP and CNP decrease cardiac preload, but unlike ANP and BNP, CNP is not natriuretic. While ANP and BNP have been localized to the heart, recent investigations have failed to detect CNP mRNA in the myocardium although small concentrations of CNP are detectable in the porcine myocardium. While originally localized to the brain, recent investigations have localized CNP to endothelial cells consistent with a paracrine role for CNP in the control of vascular tone. While CNP has been detected in cardiac tissue by radioimmunoassay, no studies have demonstrated CNP localization in normal human heart by immunoelectron microscopy.


1979 ◽  
Vol 7 (1) ◽  
pp. 261-262
Author(s):  
E. V. ROWSELL

2001 ◽  
Vol 120 (5) ◽  
pp. A153-A153
Author(s):  
S MIYAMOTO ◽  
K KATO ◽  
Y ISHII ◽  
S ASAI ◽  
T NAGAISHI ◽  
...  

1950 ◽  
Vol 16 (4) ◽  
pp. 757-763 ◽  
Author(s):  
A. Leonard Sheffner ◽  
Joseph B. Kirsner ◽  
Walter L. Palmer

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