Solid fluorescence sensors obtained by functionalization of photocrosslinked water-swollen acrylic membranes with 4-piperazine naphthalimide derivatives

• Published in: Polymer (Guilford) Vol. 124; pp. 139 - 150
• Main Authors: Fernández-Alonso, S., Corrales, T., Pablos, J.L., Catalina, F.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 25.08.2017; Elsevier BV
• Subjects: Acrylics; Chlorides; Crosslinking; Crosslinking polymerization; Derivatives; Electron transfer; Ethylene glycol; Fluorescence; Fluorescent indicators; Hydrogen ions; Membrane functionalization; Membranes; Naphthalimide fluorescence probe; pH effects; Photochemicals; Photopolymerization; Piperazine; Quenching; Sensitivity enhancement; Sensors; Membrane functionalization; Photopolymerization; Naphthalimide fluorescence probe
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/j.polymer.2017.07.039

A photocrosslinked membrane (M-Cl) based on vinyl-pyrrolidone/butyl acrylate containing ethylene glycol dimethacrylate as a crosslinking agent and methacryloyl chloride as reactive monomer has been prepared for further functionalization. A series of hydroxy substituted piperazine naphthalimide compounds have been synthetized as pH sensitive Off-On fluorescence probes using two methods: microwave and reflux. Three of the derivatives were selected to be anchored to the M-Cl membrane through the acid chloride groups by the Schotten-Baumann reaction. All the obtained water-swollen membranes were characterized using different techniques. Photo-induced electron transfer (PET) and its pH-dependent optical changes were investigated and various photochemical parameters were determined by using pH-dependent absorption and fluorescence spectroscopies. In the pH range of 9.0–4.0, these solid sensors undergo PET process from the piperazine to the naphthalimide moiety leading to a fluorescence quenching. However, in the pH range of 4.0–1.0, the PET is inhibited to give a fluorescence enhancement. The sensitivity of the functionalized membranes to pH changes depended on the size and position of the naphthalimide substituents. [Display omitted] •Photocrosslinked membranes have been functionalized with naphthalimide derivatives.•A series of hydroxyl-piperazine-naphthalimide derivatives have been synthetized.•The water-swollen functionalized membranes were characterized by different techniques.•The new functionalized membranes could be used as “Off-On” pH-fluorescence sensors.