[en] Nowadays there are a lot of multi-resistant bacteria that have to be dealt with. One of the infections with the worst prognostic that patients acquire in hospitals is caused by the bacterium Pseudomona aeruginosa. This bacterium secretes an enzyme called elastase B abroad, which has the function of cutting specific peptide sequences such as -GLA- from their substrates, as well as producing tissue and hemorrhagic lesions. For this reason, there is great interest in developing sensors for the detection and monitoring of LasB activity, thus achieving the detection of the bacterium of interest. In this final degree project, a sensor consisting of a macrocyclic complex of Eu(III) linked to a peptide containing the specific cutting sequence of the enzyme was designed and synthesized, to which 1,8-naphthalimide was added. on a side chain of an amino acid, which acts as a sensitizing unit for the metal complex. The operation of the probe consists in the production of luminescence emission by the lanthanide. The proposed detection mechanism is based on the loss of luminescence of the sensor produced after its degradation by the enzyme in two fragments in which the antenna and the metal complex are not close enough for the energy transfer to be efficient. Peptide synthesis was carried out using the solid phase method, introducing a macrocyclic complex, derived from DO3A, and the antenna following protocols described in the bibliography. To detect the bacterium, studies are carried out on the photophysical properties of the Eu(III) peptide complex and its ability to monitor the activity of the LasB enzyme.

[gl] Na actualidade hai un montón de bacterias multi-resistentes ás que lle hai que facer fronte. Unha das infeccións con peor pronóstico que adquiren os enfermos nos hospitais é a ocasionada pola bacteria Pseudomona aeruginosa. Esta bacteria secreta ao exterior unha enzima denominada elastasa B, a cal ten a función de cortar secuencias peptídicas específicas coma por exemplo, -GLA- dos seus substratos ademais de, producir lesións tisulares e hemorráxicas. Por esta razón, existe un gran interese en desenvolver sensores para a detección e monitorización da actividade da LasB, permitindo así realizar a detección da bacteria de interese. Neste traballo de fin de grao, deseñouse e se sintetizou un sensor formado por un complexo macrocíclico de Eu(III) unido a un péptido que contén a secuencia de corte específico da enzima e ao que se lle engadiu 1,8-naftalimida nunha cadea lateral dun aminoácido, que actúa como unidade sensibilizadora do complexo metálico. O funcionamento da sonda consiste na produción de emisión de luminescencia por parte do lantánido. O mecanismo de detección proposto basease na perda de luminescencia do sensor producida tras a degradación deste pola enzima en dous fragmentos no que a antena e o complexo metálico non están próximos como para que a transferencia de enerxía sexa eficiente. A síntese do péptido levouse a cabo mediante o método de fase sólida introducindo un complexo macrocíclico, derivado de DO3A, e a antena seguindo protocolos descritos na bibliografía. Para a detección da bacteria lévanse a cabo estudos das propiedades fotofísicas do complexo peptídico de Eu(III) e da súa capacidade para monitorizar a actividade da enzima LasB.