Moro, Artur J.Santos, MiguelOutis, ManiMateus, PedroPereira, Pedro Matos2021-05-032021-05-032020-09-222079-6374PURE: 20124686PURE UUID: 8d57e303-2a8a-4410-a803-b5bceed51d55Scopus: 85091619808PubMed: 32971802PubMedCentral: PMC7558417WOS: 000578179600001ORCID: /0000-0001-8973-1595/work/93186239http://hdl.handle.net/10362/116889UIDB/50006/2020 SFRH/BD/120985/2016 Project LISBOA-01-0145-FEDER-007660 PPBI-POCI-01-0145-FEDER-022122 DL 57-021/DL/2018 ROTEIRO/0031/2013-PINFRA/22161/2016A new fluorescent chemosensor for copper (II) and subsequent anion sensing was designed and fully characterized. The sensor consisted of a 1,8-naphthalimide core, bearing two terminal dipicolylamine (DPA) receptor units for binding metal cations, and an ethoxyethanol moiety for enhanced water solubility. The DPA units are connected to position 4 of the fluorophore via a triazine-ethylenediamine spacer. Fluorescence titration studies of the chemosensor revealed a high selectivity for Cu2+ over other divalent ions, the emissions were strongly quenched upon binding, and a stability constant of 5.52 log units was obtained. Given the distance from DPA chelating units and the fluorophore, quenching from the Cu2+ complexation suggests an electron transfer or an electronic energy transfer mechanism. Furthermore, the Cu2+-sensor complex proved to be capable of sensing anionic phosphate derivatives through the displacement of the Cu2+ cation, which translated into a full recovery of the luminescence from the naphthalimide. Super-resolution fluorescence microscopy studies performed in HeLa cells showed there was a high intracellular uptake of the chemosensor. Incubation in Cu2+ spiked media revealed a strong fluorescent signal from mitochondria and cell membranes, which is consistent with a high concentration of ATP at these intracellular sites.3234543engcopper (II)fluorescent chemosensornaphthalimidephosphate derivativessuper-resolution fluorescence microscopyClinical Biochemistryjournal article10.3390/bios10090129https://www.scopus.com/pages/publications/85091619808