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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Pendant-drop method coupled to ultraviolet-visible spectroscopy: A useful tool to investigate interfacial phenomena

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Andrade, Marco A. R. ; Favarin, Bruno ; Derradi, Rafael ; Bolean, Mayte ; Simao, Ana Maria S. ; Millan, Jose Luis ; Ciancaglini, Pietro ; Ramos, Ana P.
Total Authors: 8
Document type: Journal article
Web of Science Citations: 3

UV-vis spectroscopy is a powerful tool to investigate surface phenomena. Surface tension measurements coupled to spectroscopic techniques can help to elucidate how the interface organization influences the electronic properties of molecules. However, appreciable sample volumes are usually necessary to achieve strong signals during conduction of experiments. This study reports on the simultaneous acquisition of surface tension data and UV-vis spectra by axisymmetric drop shape analysis (ADSA) coupled to diffuse reflectance (DRUV) spectrophotometry using a pendant microliter-drop that requires small sample volumes and low analyte concentrations. Three example systems gave evidence of the applicability of this technique: (a) disaggregation of an organic dye driven by surfactant as a function of the surface tension and alterations in the UV-vis spectra, (b) activity of a glycosylphosphatidylinositol anchored enzyme estimated from formation of a colored product, and (c) interaction between this enzyme and biomimetic membrane systems consisting of dipalmitoylphosphaditylcholine and cholestenone. Apart from using smaller sample volume, this coupled technique allowed to investigate interfacial organization in the light of electronic spectra obtained in loco within a shorter acquisition time. This procedure provided precise interfacial information about static and dynamic systems. This has been the first study describing the kinetic activity of an enzyme in the presence of phospholipid monolayers through simultaneous determination of the surface tension and UV-vis spectra. (C) 2016 Elsevier B.V. All rights reserved. (AU)

FAPESP's process: 14/11941-3 - Are collagen and Annexin V responsible for the control in the biomineralization process?
Grantee:Pietro Ciancaglini
Support type: Regular Research Grants
FAPESP's process: 12/20946-3 - Study of the growth of calcium phosphates and carbonates on organic matrices deposited on mettalic supports: obtainment of osteoinductive biomaterials
Grantee:Ana Paula Ramos
Support type: Regular Research Grants
FAPESP's process: 15/00345-3 - Lipid microdomains in Langmuir-Blodgett films rich in alkaline phosphatase to obtain a Ti surface osteoinductive
Grantee:Marco Aurélio Raz de Andrade
Support type: Scholarships in Brazil - Master