Single chain polymeric nanoparticles as compartmentalised sensors for metal ions

Abstract

3,3′-Bis(acylamino)-2,2′-bipyridine substituted benzene-1,3,5-tricarboxamide (BiPy-BTA) grafted polynorbornene polymers were prepared via ring-opening metathesis polymerisation using a third generation Grubbs catalyst. The polymers fold intramolecularly via π–π interactions into fluorescent, compartmentalised particles of nanometer-size in mixtures of tetrahydrofuran and methylcyclohexane. Spectroscopic and light scattering techniques show that the compact conformation of the folded polymer is affected by increasing the BiPy-BTA functionalisation degree and by changing the solvent polarity. Changes in the conformation are accompanied by changes in the fluorescence intensity. Due to the affinity of the 2,2′-bipyridine units for metal ions such as copper, the particles obtained are effective sensors for these metals. The compartmentalisation of the binding motifs in SCPNs proves to be advantageous in sensor applications of these particles.