Aplicação do extrato bruto de colinesterases (che) na construção de biossensores amperométricos para gás de guerra (sarin-gb).

Abstract

When the chemical war is compared to the biological and nuclear wars, it is probably one of the most brutal ones. The chemical weapons utilized are constructed cheaply and easily produced, weapons of mass destruction. Due to its destructive application, high toxicity, simple production, and quick and lethal action even in low concentrations, it is attracting a huge military and terrorist interest. Some neurotoxic are organophosphates compounds similar to many commercially available pesticides. The OP’s can be considered as weapons of mass destruction because they are simple easily fabricated, disperse well in the atmosphere, it is difficult to detect, and has the potential to kill hundreds of people in a single attack. They act inhibiting the cholinesterase (ChE), which are enzymes from the nervous system, which control the impulses and transmissions of the nervous stimuli. Those can be obtained, respectively, from crude extracts of many tissues, like the fish’s, mammal’s and bird’s cerebral and muscular tissue. This project objective was to immobilize in mesoporous silica SBA-15, ChE, from Paralichthys patagonicus (white sole), brains crude extract, rating the enzymatic activity without the presence of the Paraoxon-ethyl xenobiotic (similar to Sarin) inhibitor, and with its presence. Detect and quantify the Cholinesterase iodide substrate in potentiostat, utilizing the square wave voltammetry technique. As a result of the literature review, three articles used the mesoporous silica as immobilization matrix but were not identified in the searched literature, biosensors built with ChE immobilized in mesoporous silica SBA-15, utilized for the nervous agent Paraoxon-ethyl (similar to Sarin) detection. The mesoporous silica SBA-15 has shown to be a reliable and stable matrix for the immobilization by ChE adsorption, contained in the crude extract. The tests of IC50, enzyme inhibition have detected the Paraoxon-ethyl in a 2,18 x 10-4 mmol.L-1 concentration, showing how sensible can be the inhibitor detection in an aqueous medium. The method developed and applied in the potentiostat was effective for the detection and quantification in the 1,25 x 10-4 1,32 x 10-3 mol.L-1 rage of the enzymatic substrate in an aqueous medium, willing to be used for measure the ChE enzymatic inhibition, in the carbon glassy carbon electrode. Key words: Biosensor. Cholinesterase. Chemical weapons. Paraoxon-ethyl (similar to Sarin).