New immunochemical approaches for Multiplexed diagnostics

Abstract

The central topic of this thesis has been the study, development and validation of diverse multiplexed diagnostics platforms and techniques that can be applied to a wide range of topics, from environmental monitoring to clinical diagnosis. A multiplexed system is distinguished by its ability to measure simultaneously several analytes from a single sample, usually offering simultaneously high-throughput and easy-to-use protocols. Two categories have been described in order to fulfill this demand: (i) spatial separation of detection sites, by means of different spots, wells, regions of a channel network or electrode arrays, or (ii) the use of various labels such as enzymes, redox molecules, beads or dyes. The different goals achieved in this thesis are related to the development of multiplexed assays for two problematic scenarios: the environmental monitoring of man-made contaminants and the attempt to improve the actual diagnostic tools in two relevant clinical fields such as infectious and cardiovascular diseases. The first scenario has been explored through the development of a different multianalyte and multiplexed platforms for the multidetection of environmental pollutants. Families of contaminants with different chemical natures have been explored, being representatives of herbicides, antibiotics, hormones, insecticides, industrial contaminants and algal toxins, the final chosen in this thesis. The research of second topic has been carried on through progressing in two different lines. On one hand, a photosensible dual-system based on plasmonic nanoparticles as a possible and innovative diagnostic tool for pathogenic bacteria involved in respiratory disease and sepsis was explored. On the other hand, the preliminary validation of a new diagnostic platform based on nonrigid PDMS chips was explored. The study of this new material and the multiple possibilities the flexible material offer regarding microfluidics design, miniaturization and functionalization could be useful for the potential development of future multiplexed platforms.