Sulfobutylether ?eta cyclodextrin/ Porphirins nanocomplexes for pathogens sensing

The detection and monitoring of pathogen bacteria in water resources is a current challenging issue. Within our ongoing research on photodiagnostics, here we propose complexes based on the trade sulfobutylether-beta-cyclodextrin (Captisol®) entrapping the cationic porphyrin (N-methyl-4 pyridyl)-21H,23H-porphyrin (H2T4) [1, 2] as nanomaterials for pathogen sensing. Nanoassemblies were prepared at different Captisol®/porphyrin molar ratio, at high entrapment efficiency by simple mixing components aqueous solutions and characterized by UV-Vis and Steady -State Fluorescence Emission, Dynamic Light Scattering and Z-potential. In order to fabricate a diagnostic kit for pathogen sensing, stability of the nanocomplexes was studied in ultrapure and simulated sea water, in different containers and temperatures mimicking selected sea basins. In order to evaluate the sensing properties of free H2T4 and Captisol®/H2T4 nanoassemblies, the interaction with a wild strain of E. coli isolated from wastewater was investigated by steady-state and time-resolved fluorescence emission. Spectroscopic results preliminarily pointed out on cationic porphyrin binding with bacterial cell, both as free fluorophore and delivered by cyclodextrin. These evidence open the way to the development of novel nanodiagnostics based on cyclodextrin and porphyrins. The authors acknowledge financing from PON ARS01_00333_TETI "TEcnologie innovative per il controllo, il moniToraggio e la sIcurezza in mare. [1] Castriciano, M. A.; Zagami, R.; Casaletto, M. Martel, B.; Trapani, M.; Romeo, A.; Villari, V.; Sciortino, M. T.; Grasso, L.; Gugliemino, S.; Monsù Scolaro, L. and A. Mazzaglia (2017), Biomacromolecules,18, 1134-1144. [2] Zagami, R.; Franco, D.; Pipkin, J. D.; Antle, V.; De Plano, L.; Patanè, S.; Guglielmino, S.; Monsù Scolaro, L. A. Mazzaglia A.,(2020) Int. J. Pharm., 585, 119487.