Switching of nanoparticles' fluorescence between "ON" and "OFF" states by a thermoresponsive polymeric layer
- Fluorescent nanoparticles that “light up”/”dim down” by applying external stimuli are of particular interest in the fields of sensing, diagnostics, photonics, protective coatings and microfluidics. The current challenge for these materials is to combine for instance fluorescence and its response to a stimulus such as temperature in a precise manner. Here we present such a system based on a core/shell/shell architecture consisting of a silica core with a fluorescent layer and a thermoresponsive shell.
The silica core nanoparticles were first coated with a fluorescent shell using surface initiated reversible addition-fragmentation chain transfer (RAFT) polymerization. The fluorescent nanoparticles were then completely engulfed by a switchable protective coating made of thermoresponsive poly(N-isopropylacrylamide). The fluorescence of the nanoparticles could be “switched on” at room temperature and “switched off” with increasing environmental temperature because of the presence of theFluorescent nanoparticles that “light up”/”dim down” by applying external stimuli are of particular interest in the fields of sensing, diagnostics, photonics, protective coatings and microfluidics. The current challenge for these materials is to combine for instance fluorescence and its response to a stimulus such as temperature in a precise manner. Here we present such a system based on a core/shell/shell architecture consisting of a silica core with a fluorescent layer and a thermoresponsive shell.
The silica core nanoparticles were first coated with a fluorescent shell using surface initiated reversible addition-fragmentation chain transfer (RAFT) polymerization. The fluorescent nanoparticles were then completely engulfed by a switchable protective coating made of thermoresponsive poly(N-isopropylacrylamide). The fluorescence of the nanoparticles could be “switched on” at room temperature and “switched off” with increasing environmental temperature because of the presence of the thermoresponsive layer. Insights into this phenomenon will be given based on temperature dependent fluorescence measurements and dynamic light scattering.…