STUDY OF MEMBRANE-LOADED PHOSPHOTRIESTERASE PERFORMANCE IN THE PRESENCE OF SURFACTANTS

The presence of recalcitrant micropollutants in the environment is a serious thread for health. Due to the persistent use of pesticides in agriculture, they accumulated in water sources and contribute to deteriorate land thus impacting also on food safety. In this scenario, the development of point-of-end with high selectivity and sensitivity able to detect trace microcontaminants is extremely urgent. The Project SmartMatter, funded within the M-ERA.NET call 2019, aims at developing smart materials able to significantly enhance the performance of state-of-the-art biosensors. In general, these devices consist of two main functions: 1) a selective recognition of the analyte by a bioreceptor and 2) the transduction of the biochemical signal into a physical signal that can be easily detected. To enhance sensitivity of the instrument, the devise should be able to locally increase the concentration of the trace analyte. In our previous works we have demonstrated the possibility to i) enhance the concentration of interleukin 6 by means of highly ordered immuno-functionalized membranes [1], ii) distribute ironbased biofunctionalized nanoparticles on the membrane surface under the action of a magnetic field [2], iii) formulate biofunctionalized emulsions and solid nanoparticles able to preserve native enantioselectivity of immobilized enzyme [3]. Based on these results, we hypothesized that the immobilization of enzymes on core-shell magnetoplasmonic spherical nanoparticles evenly distributed in a porous polymeric membrane matrix would promote significant advances of biosensors selectivity and sensitivity. The phosphotriesterase (PTE) enzyme and the paraoxon pesticide were used as bioreceptor and analyte models, respectively. The spherical topography prevents crowding phenomena, which has a positive effect on enzyme selectivity and activity. Aggregation of nanoparticles remains a problem. The work will discuss strategies to overcome this challenge and illustrate perspectives to achieve hierarchically ordered nanocomposites in membrane matrix.