Desenvolvimento de sensores eletroquímicos e métodos de extração em fase sólida baseados em sistemas biomiméticos para análise de poluentes ambientais

• Ano de defesa: 2014
• Autor(a) principal: Wong, Ademar [UNESP]
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual Paulista (Unesp)
• Palavras-chave em Português: Nanotecnologia; Eletrodos; Analise eletroquimica; Produtos químicos agrícolas; Compostos organometalicos; Polimeros; Polymers
• Link de acesso: http://hdl.handle.net/11449/124524

This work presents the development of systems using biomimetic compounds for determination of environmental pollutants. The first proposed biomimetic system is based on modification of electrodes with supramolecular compounds of phthalocyanine or porphyrin metal, that mimicked the iron protoporphyrin IX (active site of P450 enzymes). The complex evaluated in this work allowed the constructed sensors with some advantageous characteristics such as excellent catalytic activity and high electronic transfer. The verification of the biomimetization was performed through data obtained by amperometry and square-wave voltammetry. The complexes used in this study as potential catalysts P450 enzyme for monitoring of pesticides 2,4-D, diuron, carbofuran and the drug diclofenac were, respectively, the chlorine 5,10,15,20-tetrakis(pentafluorofenil)-21H22,23H-porphyrin iron (III); the 29H,31H)-phthalocyanine-1,4,8,11,15,18,22,25-octabutoxi nickel (II); the hemin and 29H,31H)-phthalocyanine-1,4,8,11,15,18,22,25-octabutoxi copper (II). Furthermore, during this period a sensor was developed for the detection of thiram using carbon nanotube modified electrode. The proposed sensors showed in batch and flow (FIA) systems, sensitivity between 1.0 x 104 and 1.1 x 105 L mol-1 μA and a detection limit between 2.0 x 10-6 and 1.3 x 10-5 mol L-1. When evaluated the selectivity of the sensor with other compounds was observed high selectivity, for example, the biomimetic sensor showed only electrochemical signal for diuron when performed amperometry in potential of 0.75 V. The compounds were carbofuran, thiram, chlorpyrifos, metribuzin, 2,4-D, hexazinone, ametryn, profenofos and carbendazim. The stability and reproducibility of the sensors were realized satisfactory with calibration curves with RSD of 4%. When applied to real samples (soil samples, water from rivers, biological serum, pharmaceutical formulations), the results...