Polydiacetylene-based gels for solvent discrimination and formation of Au/Ag nanoparticles with embedded photocatalytic performance

two novel gelators N-TPY-DA and O-TPY-DA were designed. By introduction of Eu3+ followed by UV-irradiation, Eu3+/O-TPY-PDA polymeric gel with dark purple color and red emission color was obtained. Furthermore, colorimetric and fluorescent sensor arrays toward organic solvents could be obtained by Eu3+/O-TPY-PDA gels. Eu3+/O-TPY-PDA gel showed dark purple-to-red color response toward organic solvents such as CH2Cl2, CHCl3, THF and DMF. On the other hand, DMF and methanol both triggered red-to-blue emission color changes of Eu3+/O-TPY-DA gel. The two solvents could be further discriminated by fluorescent spectral difference. Furthermore, O-TPY-PDA or N-TPY-PDA gel could be also utilized to absorb Ag+ or Au3+ from aqueous solutions. By in situ reduction, the obtained fibrous xerogel assembly embedded with Ag or Au nanoparticles had enhanced photocatalytic performance. This work showed how a simple gel system converts to materials with multiple functions including pollutant sensing, absorption and functional nanoparticle formation.