title: Silsesquioxane as a new building block material for modified electrodes fabrication and application as neurotransmitters sensors.
abstract: Nanostructured films comprising a 3-n-propylpyridinium silsesquioxane polymer (designated as SiPy+Cl-) and copper (II) tetrasulfophthalocyanine (CuTsPc) were produced using the Layer-by-Layer technique (LbL). To our knowledge this is the first report on the use of silsesquioxane derivative polymers as building blocks for nanostructured thin films fabrication. Deposition of the multilayers were monitored by UV-Vis spectroscopy revealing the linear increment in the absorbance of the Q-band from CuTsPc at 617 nm with the number of SiPy+Cl-/CuTsPc or CuTsPc/SiPy+Cl-bilayers. FTIR analyses showed that specific interactions between SiPy+Cl- and CuTsPc occurred between SO3- groups of tetrasulfophthalocyanine and the pyridinium groups of the polycation. Morphological studies were carried out using the AFM technique, which showed that the roughness and thickness of the films increase with the number of bilayers. The films displayed electroactivity and were employed to detection of dopamine (DA) and ascorbic acid (AA) using cyclic voltammetry, at concentrations ranging from 1.96 x 10(-4) to 1.31 x 10(-3) molL(-1). The number and the sequence of bilayers deposition influenced the electrochemical response in presence of DA and AA. Using differential pulse technique, films comprising SiPy+/-/CuTsPc were able to distinguish between DA and ascorbic acid (AA), with a potential difference of approximately with 500 mV, in the concentration range of 9.0 x 10(-5) to 2.0 x 10(-4) molL(-1), in pH 3.0.
authors.affiliation: Department de Química, Universidade Estadual de Ponta Grossa, 84030-900, Ponta Grossa - PR, Brazil.
authors.forename: Cliciane Guadalupe
authors.initials: CG
authors.lastname: de Jesus
authors.forename: Vagner
authors.initials: V
authors.lastname: dos Santos
authors.forename: Carla Daniele
authors.initials: CD
authors.lastname: Canestraro
authors.forename: Valtencir
authors.initials: V
authors.lastname: Zucolotto
authors.forename: Sérgio Toshio
authors.initials: ST
authors.lastname: Fujiwara
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Gushikem
authors.forename: Karen
authors.initials: K
authors.lastname: Wohnrath
authors.forename: Christiana Andrade
authors.initials: CA
authors.lastname: Pessoa
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D003217:Conductometry / Q000295:instrumentation*; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D036103:Nanotechnology / Q000295:instrumentation*; D018377:Neurotransmitter Agents / Q000032:analysis*; D017646:Organosilicon Compounds / Q000737:chemistry*
chemical_list: C512088:1,3-bis(1,1,3,3,5,5-hexaethoxy-1,3,5-trisilacyclohexyl)propane; D018377:Neurotransmitter Agents; D017646:Organosilicon Compounds