Uso do fruto do babaçu (Orbignya phalerata) na construção de sensores eletroquímicos para a determinação de cocaína e hidroxicloroquina

Abstract

The babassu palm (Orbignya sp.) is an important native species of the Amazon region in South America with significant potential for industrial applications, including biodiesel production. From the fruit components of babassu, a mixture containing 60% starch can be obtained. Despite the traditional regional uses of babassu, the properties of this starch have not yet been explored for the construction of modified electrodes. Nanomaterials such as carbon black (CB), a low-cost nanostructured material (-$1 per kg) with excellent electrochemical properties, have received special attention for applications in electrochemical devices, including (bio)sensors. This dissertation presents two studies on the development of electrochemical sensors using materials derived from babassu coconut, both employing carbon black as a conductive material. The first study describes a glassy carbon electrode modified with starch extracted from babassu coconut mesocarp, Super P carbon black, and cobalt phthalocyanine, which was used to determine hydroxychloroquine. The method achieved detection and quantification limits of 0.015 umol L-1 and 0.052 umol L-1, respectively. When applied to tap water, water treatment plant (W'TP) samples, and pharmaceutical products, the method demonstrated recovery rates close to 100%. The second study involved the development of a conductive filament composed of edible oil extracted from babassu coconut kernels, carbon black, and PLA pellets. This filament was used to produce electrodes through 3D printing. The fabricated electrodes were employed for cocaine determination, showing detection and quantification limits of 1.2 umol L”! and 3.9 umol L”!, respectively. The method was successfully applied to analyze cocaine samples seized by the Federal Police in Minas Gerais state, containing various interferents, with recovery rates ranging between 88- 102%.