We report that the efflux of 5(6)-carboxyfluorescein anions from neutral egg yolk phosphatidylcholine vesicles is mediated by oligo/polyarginines only in the presence of activating amphiphilic anions. Screening of anion activators reveals best synergism for amphiphilic carboxylates (fullerene > calix[4]arene approximately coronene > pyrene > calix[6]arene > alkyl), whereas amphiphilic sulfates show less satisfactory activation despite often lower effective concentrations. The analogous alcohols and one calix[4]arene diphosphate were inactive. These results are discussed in the context of a tentative anion carrier mechanism, where interactions with bilayer (interface-directed translocation) and carrier (arene-templated carboxylate-guanidinium pairing) contribute to activator efficiencies. Applied to HeLa cells, pyrenebutyrate is shown to significantly increase the uptake of a fluorescently labeled octaarginine in a concentration-dependent manner.
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Sensors (Basel)
December 2024
Escuela de Ciencias Químicas, Pontificia Universidad Católica del Ecuador, Quito 170525, Ecuador.
This work reports on the assessment of a non-hydrolytic electrochemical sensor for glucose sensing that is developed using functionalized carbon nanotubes (fCNTs)/Co(OH). The morphology of the nanocomposite was investigated by scanning electron microscopy, which revealed that the CNTs interacted with Co(OH). This content formed a nanocomposite that improved the electrochemical characterizations of the electrode, including the electrochemical active surface area and capacitance, thus improving sensitivity to glucose.
View Article and Find Full Text PDFbioRxiv
December 2024
Department of Chemistry, Chicago Center for Theoretical Chemistry, Institute for Biophysical Dynamics, and James Franck Institute, The University of Chicago, Chicago, IL 60637, United States of America.
HIV-1 capsid proteins (CA) self-assemble into a fullerene-shaped capsid, enabling cellular transport and nuclear entry of the viral genome. A structural switch comprising the Thr-Val-Gly-Gly (TVGG) motif either assumes a disordered coil or a 3 helix conformation to regulate hexamer or pentamer assembly, respectively. The cellular polyanion inositol hexakisphosphate (IP6) binds to a positively charged pore of CA capsomers rich in arginine and lysine residues mediated by electrostatic interactions.
View Article and Find Full Text PDFInt J Mol Sci
November 2024
School of Science, Northeast Electric Power University, Jilin 131200, China.
Confining protons into an enclosed carbon cage is expected to give rise to unique electronic properties for both the inner proton and the outer cage. In this work, we systematically investigated the geometric and electronic structures of cationic X@C (X = H, HO, and NH), and their corresponding neutral species (X = HO, NH), by quantum chemical density functional theory calculations. We show that C can trap HO, NH, HO and NH at the cage center and only slightly influence their geometries.
View Article and Find Full Text PDFTalanta
March 2025
School of Textile Science and Engineering, Tiangong University, Tianjin 300387, China; Key Laboratory of Advanced Textile Composites, Ministry of Education, Tiangong University, Tianjin 300387, China; National Innovation Center of Advanced Dyeing & Finishing Technology, Tai'an, Shandong 271000, China; Collaborative Innovation Center for Eco-Textiles of Shandong Province, Shandong, Qingdao 266071, China.
Wearable sweat sensing devices have drawn much attention due to their noninvasive and portable properties, which is emerging as a promising technology in daily healthiness assessment issues. A sweat sensor based on Janus fabric and electrochemical analysis is proposed in this work. Unidirectional moisture transported behavior of the Janus fabric serves as the quick-drying component directly contacting skin to transfer sweat toward the detection site.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
Department of Chemistry, College of Science, Jouf University, PO Box 2014, Sakaka, Aljouf, Saudi Arabia. Electronic address:
This study details the development and evaluation of sodium alginate-Poly(acrylonitrile-co-styrene)/ Carbon Nanotubes (SA-M*Poly(AN-co-ST)/CNTs) composite beads serve as a highly effective adsorbent for the removal of Fe(II) ions from water solutions. The composite was prepared through the modification and functionalization of poly(acrylonitrile-co-styrene) copolymer with carboxylic acid groups, Subsequently, carbon nanotubes (CNTs) and sodium alginate were integrated to create sturdy gel beads. The composite beads were characterized using SEM, FTIR, and BET surface analysis spectroscopy, revealing a specific surface area of 127.
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