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

Autor(es)

Andrade, Marco A. R. ; Favarin, Bruno ; Derradi, Rafael ; Bolean, Mayte ; Simao, Ana Maria S. ; Millan, Jose Luis ; Ciancaglini, Pietro ; Ramos, Ana P.

• Tipo de documento: Artigo Científico
• Fonte: COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS; v. 504, p. 305-311, SEP 5 2016.
• Citações Web of Science: 3

Resumo

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)

• Processo FAPESP: 14/11941-3 - Colágeno e annexina são responsáveis pelo controle do processo de biomineralização?
• Beneficiário: Pietro Ciancaglini
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 12/20946-3 - Estudo do crescimento de fosfatos e carbonatos de cálcio sobre matrizes orgânicas depositadas sobre suportes metálicos: obtenção de biomateriais osteoindutores
• Beneficiário: Ana Paula Ramos
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 15/00345-3 - Microdomínios lipídicos em filmes Langmuir-Blodgett ricos em fosfatase alcalina para obtenção de uma superfície de Ti osteoindutora
• Beneficiário: Marco Aurélio Raz de Andrade
• Modalidade de apoio: Bolsas no Brasil - Mestrado