< Terug naar vorige pagina
Publicatie
PFAS sensing
Boek - Dissertatie
Ondertitel:concept design of electrochemical and optical, bio- and biomimetic strategies
PFASensing focuses on the concept design of electrochemical and optical, bio- and biomimetic strategies for the quantitative or semi-quantitative determination of per- and polyfluorinated alkyl substances (PFAS). PFAS are a class of more than 3000 manmade chemicals, which represent a global issue due to their bioaccumulation and toxic behavior. Therefore, they are subjected to strict regulatory plans and numerous sensing platforms have been reported for the rapid quantification or qualitative screening of these pollutants. The applicability of the existing analytical tools is limited by the challenges of the technological transfer processes and the never-ending evolution of PFAS molecules. Aiming to transpose toxicological studies in PFAS biosensing design, we follow the changes in the electrochemical behaviour of globins upon PFAS exposure supporting our data interpretation with native mass spectrometry. Also delipidated human serum albumin was considered for application in PFAS sensing. We designed a multi-analytical approach to assess the binding kinetics, stoichiometry and stability of albumin-perfluorooctanoic acid (PFOA) complex, here PFOA was selected as representative of PFAS class. Then, albumin was applied as bioreceptor in an impedimetric label-free biosensor for determining PFOA. The protein bioreceptor was immobilized at screen-printed electrodes previously modified via electropolymerisation developing a method compatible with EDC/NHS chemistry. The possibility to further combine albumin bioreceptor within a voltammetric sensing strategy was investigated using a natural redox probe, the haem group. Heam interaction with albumin depends on the protein conformation and this latter can be indirectly related to the presence/absence of PFOA. Albumin was immobilized even at D-shaped optical fibers developing a Lossy-Mode Resonance-based label-free platform. This proof-of-concept study is one of the first examples in which this kind of optical sensors is used for the determination of small molecules, such as PFOA. Apart from testing new strategies, PFASensing redesigned existing PFAS sensors, in particular a molecularly imprinted polymer (MIP)-based voltammetric sensors for perfluorosulfonic acid (PFOS) aiming to advance in the technological transfer process. This MIP single-substance platform was further compared with a screening strategy based on fluorinated self-assembled monolayers (SAM). The electrochemical study of the changes in different fluorinated SAM upon exposure to long-chain and short-chain PFAS was supported by molecular dynamic simulations. PFASensing started answering the need of investigating new bio- and biomimetic sensing strategies by applying structural biology analysis in bioreceptor design, combing and comparing different sensing platforms, redesigning existing sensors and testing possible screening method. Overall, this study offers useful guidelines for the development of new sensing strategies for PFAS monitoring in different environmental matrices.
Aantal pagina's: 237
Jaar van publicatie:2021
Trefwoorden:Doctoral thesis
Toegankelijkheid:Open