scholarly journals Affinity of Electrochemically Deposited Sol–Gel Silica Films towards Catecholamine Neurotransmitters

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 868
Author(s):  
María Porcel-Valenzuela ◽  
Francisco Huerta ◽  
Emilia Morallón ◽  
Francisco Montilla
Keyword(s):  
Electrochemical Sensors ◽  
Sol Gel ◽  
Silica Films ◽  
Glassy Carbon Electrodes ◽  
Similar Chemical ◽  
Electrochemically Deposited ◽  
Amine Groups ◽  
Silica Layers ◽  
Electroassisted Deposition ◽  
Selective Analysis

Dopamine, norepinephrine, and epinephrine neurotransmitters can be detected by electrochemical oxidation in conventional electrodes. However, their similar chemical structure and electrochemical behavior makes a difficult selective analysis. In the present work, glassy carbon electrodes have been modified with silica layers, which were prepared by electroassisted deposition of sol–gel precursors. These layers were morphologically and compositionally characterized using different techniques, such as field emission scanning electron microscopy (FESEM), TEM, FTIR, or thermogravimetric analysis–mass spectrometry (TG-MS). The affinity of silica for neurotransmitters was evaluated, exclusively, by means of electrochemical methods. It was demonstrated that silica adsorbs dopamine, norepinephrine, and epinephrine, showing different interaction with silica pores. The adsorption process is dominated by a hydrogen bond between silanol groups located at the silica surface and the amine groups of neurotransmitters. Because of the different interaction with neurotransmitters, electrodes modified with silica films could be used in electrochemical sensors for the selective detection of such molecules.

Electrochemical Behaviour of PSS-Functionalized Silica Films Prepared by Electroassisted Deposition of Sol–Gel Precursors

2014 ◽  
Vol 6 (1) ◽  
pp. 33-41 ◽  
Author(s):  
Alonso Gamero-Quijano ◽  
Francisco Huerta ◽  
David Salinas-Torres ◽  
Emilia Morallón ◽  
Francisco Montilla
Keyword(s):  
Electrochemical Behaviour ◽  
Sol Gel ◽  
Functionalized Silica ◽  
Silica Films ◽  
Electroassisted Deposition

Nanostructured Doped Silica Films Application as Sensitive Layers for Chemical Sensors

2013 ◽  
Vol 684 ◽  
pp. 7-11
Author(s):  
Sergey Krutovertsev ◽  
Alla Tarasova ◽  
Olga Ivanova ◽  
Larisa Krutovertseva
Keyword(s):  
Initial Conditions ◽  
Sol Gel ◽  
Silica Films ◽  
Adsorption Activity ◽  
Developed Surface ◽  
Sol Gel Process ◽  
Sensitive Characteristics ◽  
The Right ◽  
Kinetics Of ◽  
Matrix Factors

The sensor behavior of nanostructured doped silica films produced by sol-gel way were examined. Hygroscopic substances and polyoxometalates were used as additives to make more significant sensitive characteristics of initial matrix. Factors that have effect on sol preparation and films forming were investigated. Adsorption activity of the sensitive films was studied and it was shown that the films had a highly developed surface with nano-size pores. Change of initial conditions of sol-gel process gives opportunity to influence on kinetics of gel formation and consequently, on structure and properties of final materials. The study showed that the conditions of the environment affected the sensors characteristics markedly, which can be improved by choosing of the right procedure of forming and treatment. Influence of type and additive substances quantity into doped films was discussed in the paper

Sol-gel process of non-linear optical silica films with organic chromophore as side chain

1996 ◽  
Vol 31 (9) ◽  
pp. 2443-2446 ◽  
Author(s):  
Po-Hou Sung ◽  
Shao-Ling Wu ◽  
Chien-Yang Lin
Keyword(s):  
Sol Gel ◽  
Side Chain ◽  
Silica Films ◽  
Sol Gel Process ◽  
Non Linear ◽  
Linear Optical ◽  
Organic Chromophore

Sol–gel derived mesoporous silica films using amphiphilic triblock copolymers

2003 ◽  
Vol 332 (1-3) ◽  
pp. 199-206 ◽  
Author(s):  
Nobuaki Kitazawa ◽  
Hideyoshi Namba ◽  
Masami Aono ◽  
Yoshihisa Watanabe
Keyword(s):  
Mesoporous Silica ◽  
Triblock Copolymers ◽  
Sol Gel ◽  
Silica Films

Sol-Gel Derived Silica Layers for Low-k Dielectrics Applications

2000 ◽  
Vol 612 ◽  
Author(s):  
Sylvie Acosta ◽  
André Ayral ◽  
Christian Guizard ◽  
Charles Lecornec ◽  
Gérard Passemard ◽  
...  
Keyword(s):  
Average Pore Size ◽  
Sol Gel ◽  
Porous Silica ◽  
Thin Layers ◽  
Gaseous Ammonia ◽  
Potential Candidate ◽  
Average Pore ◽  
Synthesis Strategy ◽  
Silica Layers ◽  
Highly Porous

AbstractPorous silica exhibits attractive dielectric properties, which make it a potential candidate for use as insulator into interconnect structures. A new way of preparation of highly porous silica layers by the sol-gel route was investigated and is presented. The synthesis strategy was based on the use of common and low toxicity reagents and on the development of a simple process without gaseous ammonia post-treatment or supercritical drying step. Defect free layers were deposited by spin coating on 200 mm silicon wafers and characterized. Thin layers with a total porosity larger than 70% and an average pore size of 5 nm were produced. The dielectric constant measured under nitrogen flow on these highly porous layers is equal to ∼ 2.5, which can be compared to the value calculated from the measured porosity, ∼ 1.9. This difference is explained by the presence of water adsorbed on the hydrophilic surface of the unmodified silica.

Chemical Analyses of Sol/Gel Surfaces and Thin Films

1984 ◽  
Vol 32 ◽  
Author(s):  
Carlo G. Pantano ◽  
C. A. Houser ◽  
R. K. Brow
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Silica Films ◽  
Alumina Films ◽  
Surface Analysis Techniques ◽  
Relative Water ◽  
Temperature Programmed

ABSTRACTThe application of surface analysis techniques to the characterization of sol/gel surfaces and thin films is described. Secondary-ion mass spectroscopy (SIMS), x-ray photoelectron spectroscopy (XPS) and sputter-induced photon spectroscopy (SIPS) are used to measure the composition of multicomponent silicate films, the relative water content of alumina films, the nitrogen content of ammonia treated silica films, and the depth profiles for films on black chrome. The determination of chemical structure using XPS and SIMS is also discussed. Finally, a brief introduction to temperature-programmed desorption (TPD) and its potential for studying surface chemical reactions, in situ, is presented.

ChemInform Abstract: Sol-Gel-Derived Mesoporous Silica Films with Low Dielectric Constants.

ChemInform ◽  
2001 ◽  
Vol 32 (10) ◽  
pp. no-no
Author(s):  
Seana Seraji ◽  
Yun Wu ◽  
Michael Forbess ◽  
Steven J. Limmer ◽  
Tammy Chou ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Sol Gel ◽  
Dielectric Constants ◽  
Silica Films ◽  
Low Dielectric

Stress Development in Low Dielectric Constant Silica Films During Drying and Heating Process

1999 ◽  
Vol 594 ◽  
Author(s):  
Mengcheng Lu ◽  
C. Jeffrey Brinker
Keyword(s):  
Dielectric Constant ◽  
Tensile Stress ◽  
Sol Gel ◽  
Low Dielectric Constant ◽  
Heating Process ◽  
Residual Tensile Stress ◽  
Silica Films ◽  
Stress Development ◽  
Low Dielectric

AbstractLow dielectric constant silica films are made using a surfactant templated sol-gel process (K∼2.5) or an ambient temperature and pressure aerogel process (K∼1.5). This paper will present the in-situ measurement and analysis of stress development during the making of these films, from the onset of drying till the end of heating. The drying stress is measured by a cantilever beam technique; the thermal stress is measured by monitoring the wafer curvature using a laser deflection method. During the course of drying, the surfactant templated films experience a low drying stress due to the influence of the surfactant on surface tension and extent of siloxane condensation. The aerogel films first develop a biaxial tensile stress due to solidification and initial drying. At the final stage of drying where the drying stress vanishes, dilation of the film recreates the porosity of the wet gel state, reducing the residual stress to zero. For the surfactant templated films, very small residual tensile stress remains after the heat treatment is finished (∼30MPa). Aerogel film has almost no measurable stress developed in the calcination process. In situ spectroscopic ellipsometry analysis during drying and heating, and TGA/DTA are all used to help understand the stress development.

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