[en] Full text: Some plants of the catalpa family, such as Tabebuia avellanedae have a type of flavonoid referred to lapachol, which is found in wood and bark. Lapachol is currently being researched as an anti-tumor and anti-viral compound, but some derivative has been found to interfere with the replication of HIV-1, a virus that causes AIDS, thereby slowing the advancement of the disease. Lapachol is a type of molecule capable of coordinating with various transition metal ions and can be used to make selective electrodes for detection of lapachol molecule. In this work previous synthesized silver(I)-lapachol complex was dispersed at 5wt% in porous cermet composite composed by 10wt% of metallic silver embedded in silica-alumina ceramic matrix obtained by Sol-Gel method. TEOS and aluminium nitrate were mixed in ethanol media and the pH adjusted in order to form the homogeneous gel, what was dried and grinded. Thermal analysis, XRD, FTIR and UV-Vis techniques spectroscopy were used to characterize the amorphous nature and porosity of the matrix composite, as well as the silver(I)-lapachol complex powder. The complex and matrix powders were then mixed to a slurry of mineral oil with carbon and pressed into a polyethylene tube containing a platinum wire for electrical connection. Using a Ag/AgCl reference electrode, various buffered lapachol solutions were tested according to the concentration and the first data for this new lapachol selective electrode could be tested. The next step will be to test the electrode for prospecting new plant species with potential for extraction yield. Reference: [1] SIMIONATTO, E.; BONANI, V. F. L.; MOREL, A. F. et al. J. Braz. Chem. Soc., v. 18, 879-885, 2007. [2] CARUSO, F.; MARTINEZ, M. A.; ROSSI, M. et. al. Inorg. Chem., v. 48, 3529-3534, 2009. [3] LI, W.; SUN, X.; WEN, C.; LU, H.; WANG, Z. Frontiers of Environmental Science & Engineering. V.7, n. 4, p. 492-502, 2013. (author)