One-step synthesis of fluorescent silver nanoparticles with modulated emission wavelength using oligo-polyarylene ether nitrile as surface capping agent

Abstract

It is well-known that the photonic properties of silver nanoparticles are strongly dependent on their sizes, and the photoluminescence is traditionally detected from the silver nanoparticles with ultra-small sizes <2 nm, which are also named as silver nanoclusters. In this work, a facile one-step protocol for synthesis of fluorescent silver nanoparticles with much larger size in the range of 20–70 nm was reported, where the fluorescent polyarylene ether nitrile (PEN) oligomers with different backbone structures were employed as the surface capping agents. It was found that the silver nanoparticles stabilized with PEN oligomer containing both carboxylic and sulfonic side groups (oligo-PEN/CS) exhibited much stronger luminescence when compared to those capped with carboxylated PEN oligomer (oligo-PEN/C). Furthermore, the fluorescence emission wavelength of obtained Ag nanoparticles can be modulated from 490 nm to 600 nm by simply changing the reaction time of silver ions reduction via oligo-PEN/CS at 70 °C in N,N-dimethylformamide (DMF). Based on their tailorable luminescence, the synthesized silver nanoparticles could find potential applications in biochemical sensing and advanced optical devices.