Vanessa Escobar's PhD defense

Phage Display is a powerful in vitro technique to screen phage clones displaying peptides or proteins with the highest affinity to a specific target from an initial library of highly diverse candidates. The aim of this PhD thesis was the exploration of this technique for screening highly selective peptides for the development of novel biosensors and electronic noses for the detection of foodborne pathogens, which pose an important threat to human health.

Firstly, peptides targeting the foodborne pathogen Campylobacter jejuni were obtained through Phage Display. Their binding activity towards this bacterium was characterized and validated using phage ELISA. The best-performing candidates were selected and synthetized for their future integration into biosensors for sensing bacterial cells in the liquid-phase.

Secondly, peptides targeting Volatile Organic Compounds (VOCs) were designed and selected using Phage Display and molecular docking. They were incorporated into an optoelectronic nose (opto-eN) based on Surface Plasmon Resonance Imaging (SPRI). The relevance of Phage Display for the selection of highly selective peptides was first validated using VOCs from the family BTEX (Benzene, Toluene, Ethylbenzene and Xylenes). Afterwards, the opto-eN was employed for the detection of bacteria-related VOC markers in the gas-phase.

IRIG/SyMMES Lab.