Multiple approaches for ultrasensitive quantitative analysis in complex matrices: from traditional chromatographic techniques coupled with mass spectrometry to the development of biosensors for point-of-care applications based on biospecific recognition reactions

The research activity carried out during the three years of PhD was principally addressed the development of a portable analytical device based on biospecific molecular recognition reaction (immunoassay) and chemiluminescent (CL) detection. In particular, the development of biosensors was focused on the study of the properties of different materials as well as procedures for their construction, with particular attention to the development of suitable immobilization procedures, fluidic systems, and the selection of the suitable detectors. In this context, different methods were exploited, such as immunoassay and enzymatic-based techniques, exploiting different platforms (microplate format, functionalized magnetic microbeads) trying to improve the simplicity of the assay procedure. Different CL detectors were also employed (i.e amorphous silicon photosensors, charge-coupled device) for allowing an implementation of the specific bioassays into portable analytical platforms. The work was therefore aimed at miniaturization and simplification of analytical devices and the study involved all aspects of the system, from the analytical methodology to the type of detector, in order to combine high sensitivity with easiness-of-use and rapidity. In addition to this work, studies have also been carried out using traditional bench-top analytical approaches based on chromatographic techniques coupled with mass spectrometry. These techniques have been used in projects involving the quantification of analytes of interest in complex matrices of environmental and pharmaceutical/cosmetic interest.